Move CameraFit attributes from the base class to the subclasses and t…

…idy up documentation

None of the fields which were on the CameraFit base class were
conceptually essential for any imaginable camera fit. Moving them to
the subclasses ensures that any future camera fits will not need to
implement those options just because they already exist. It would also
allow for individual camera fits to specify different default values if
appropriate.

lib/src/map/camera/camera_fit.dart

@@ -1,9 +1,9 @@
 import 'dart:math' as math;
 
 import 'package:flutter/widgets.dart';
-import 'package:flutter_map/src/map/camera/camera_constraint.dart';
 import 'package:flutter_map/src/geo/latlng_bounds.dart';
 import 'package:flutter_map/src/map/camera/camera.dart';
+import 'package:flutter_map/src/map/camera/camera_constraint.dart';
 import 'package:flutter_map/src/misc/point.dart';
 import 'package:flutter_map/src/misc/private/bounds.dart';
 import 'package:latlong2/latlong.dart';
@@ -15,27 +15,7 @@ abstract class CameraFit {
   /// Describes a position for a [MapCamera]
   ///
   /// Constraints are handled by [CameraConstraint].
-  const CameraFit({
-    this.padding = EdgeInsets.zero,
-    this.maxZoom = 18,
-    this.forceIntegerZoomLevel = false,
-  });
-
-  /// Adds a constant/pixel-based padding to the normal fit
-  ///
-  /// Defaults to [EdgeInsets.zero]
-  final EdgeInsets padding;
-
-  /// Limits the maximum zoom level of the resulting fit
-  ///
-  /// Defaults to zoom level 18.
-  final double maxZoom;
-
-  /// Whether the zoom level of the resulting fit should be rounded to the
-  /// nearest integer level
-  ///
-  /// Defaults to `false`.
-  final bool forceIntegerZoomLevel;
+  const CameraFit();
 
   /// Fits the [bounds] inside the camera
   ///
@@ -79,21 +59,31 @@ abstract class CameraFit {
   MapCamera fit(MapCamera camera);
 }
 
-/// A configuration for fitting a [MapCamera] to the given [bounds]. The
-/// [padding] may be used to leave extra space around the [bounds]. To
-/// limit the zoom of the resulting [MapCamera] use [maxZoom] (default 17.0).
-/// If [inside] is true then fit will be within the [bounds], otherwise it
-/// will contain the [bounds] (default to false, contain). Finally
-/// [forceIntegerZoomLevel] forces the resulting zoom to be rounded to the
-/// nearest whole number.
 class FitBounds extends CameraFit {
+  /// The bounds which the camera should contain once it is fitted.
   final LatLngBounds bounds;
 
+  /// Adds a constant/pixel-based padding to the normal fit.
+  ///
+  /// Defaults to [EdgeInsets.zero].
+  final EdgeInsets padding;
+
+  /// Limits the maximum zoom level of the resulting fit.
+  ///
+  /// Defaults to zoom level 18.
+  final double maxZoom;
+
+  /// Whether the zoom level of the resulting fit should be rounded to the
+  /// nearest integer level.
+  ///
+  /// Defaults to `false`.
+  final bool forceIntegerZoomLevel;
+
   const FitBounds._({
     required this.bounds,
-    super.padding,
-    super.maxZoom,
-    super.forceIntegerZoomLevel,
+    this.padding = EdgeInsets.zero,
+    this.maxZoom = 18,
+    this.forceIntegerZoomLevel = false,
   });
 
   /// Returns a new [MapCamera] which fits this classes configuration.
@@ -169,13 +159,30 @@ class FitBounds extends CameraFit {
 }
 
 class FitInsideBounds extends CameraFit {
+  /// The bounds which the camera should fit inside once it is fitted.
   final LatLngBounds bounds;
 
+  /// Adds a constant/pixel-based padding to the normal fit.
+  ///
+  /// Defaults to [EdgeInsets.zero].
+  final EdgeInsets padding;
+
+  /// Limits the maximum zoom level of the resulting fit.
+  ///
+  /// Defaults to zoom level 18.
+  final double maxZoom;
+
+  /// Whether the zoom level of the resulting fit should be rounded to the
+  /// nearest integer level.
+  ///
+  /// Defaults to `false`.
+  final bool forceIntegerZoomLevel;
+
   const FitInsideBounds._({
     required this.bounds,
-    super.padding,
-    super.maxZoom,
-    super.forceIntegerZoomLevel,
+    this.padding = EdgeInsets.zero,
+    this.maxZoom = 18,
+    this.forceIntegerZoomLevel = false,
   });
 
   @override
@@ -343,22 +350,31 @@ class FitInsideBounds extends CameraFit {
   }
 }
 
-/// A configuration for fitting a [MapCamera] to the given [coordinates] such
-/// that all of the [coordinates] are contained in the resulting [MapCamera].
-/// The [padding] may be used to leave extra space around the [bounds]. To
-/// limit the zoom of the resulting [MapCamera] use [maxZoom] (default 17.0).
-/// If [inside] is true then fit will be within the [bounds], otherwise it
-/// will contain the [bounds] (default to false, contain). Finally
-/// [forceIntegerZoomLevel] forces the resulting zoom to be rounded to the
-/// nearest whole number.
 class FitCoordinates extends CameraFit {
+  /// The coordinates which the camera should contain once it is fitted.
   final List<LatLng> coordinates;
 
+  /// Adds a constant/pixel-based padding to the normal fit.
+  ///
+  /// Defaults to [EdgeInsets.zero].
+  final EdgeInsets padding;
+
+  /// Limits the maximum zoom level of the resulting fit.
+  ///
+  /// Defaults to zoom level 18.
+  final double maxZoom;
+
+  /// Whether the zoom level of the resulting fit should be rounded to the
+  /// nearest integer level.
+  ///
+  /// Defaults to `false`.
+  final bool forceIntegerZoomLevel;
+
   const FitCoordinates._({
     required this.coordinates,
-    super.padding,
-    super.maxZoom,
-    super.forceIntegerZoomLevel,
+    this.padding = EdgeInsets.zero,
+    this.maxZoom = 18,
+    this.forceIntegerZoomLevel = false,
   });
 
   /// Returns a new [MapCamera] which fits this classes configuration.