refactor(neon_framework): rewrite login flow and account handling

[Leptopoda]

.

[provokateurin]

The following UnsupportedError was thrown running a test:
Unsupported operation: The fake account client can not be used in tests.

[codecov]

Codecov Report

Attention: Patch coverage is 86.84720% with 68 lines in your changes missing coverage. Please review.

Project coverage is 30.29%. Comparing base (c07d612) to head (26dca5d).
Report is 9 commits behind head on main.

Files with missing lines	Patch %	Lines
...n_check_account/view/login_check_account_view.dart	51.72%	14 Missing ⚠️
...lib/src/login_qr_code/view/login_qr_code_view.dart	8.33%	11 Missing ⚠️
packages/neon_framework/lib/src/router.dart	35.71%	9 Missing ⚠️
...ackages/neon_framework/lib/src/blocs/accounts.dart	0.00%	8 Missing ⚠️
.../neon_framework/lib/src/login/view/login_view.dart	88.57%	8 Missing ⚠️
...lib/src/login_qr_code/view/login_qr_code_page.dart	16.66%	5 Missing ⚠️
packages/neon_framework/lib/src/widgets/error.dart	16.66%	5 Missing ⚠️
packages/neon_framework/lib/src/router.g.dart	40.00%	3 Missing ⚠️
...ib/src/login_qr_code/bloc/login_qr_code_event.dart	71.42%	2 Missing ⚠️
.../neon_framework/lib/src/login/bloc/login_bloc.dart	96.29%	1 Missing ⚠️
... and 2 more

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2407      +/-   ##
==========================================
+ Coverage   29.91%   30.29%   +0.38%     
==========================================
  Files         332      352      +20     
  Lines      124382   124361      -21     
==========================================
+ Hits        37205    37672     +467     
+ Misses      87177    86689     -488     

Flag	Coverage Δ		*Carryforward flag
account_repository	98.77% <ø> (-0.87%)	⬇️
cookie_store	99.48% <ø> (ø)		Carriedforward from c07d612
dashboard_app	96.05% <ø> (ø)
dynamite	31.08% <ø> (ø)		Carriedforward from c07d612
dynamite_end_to_end_test	61.69% <ø> (ø)		Carriedforward from c07d612
dynamite_runtime	85.40% <ø> (ø)		Carriedforward from c07d612
neon_dashboard	96.05% <ø> (ø)		Carriedforward from c07d612
neon_framework	57.10% <86.84%> (+13.52%)	⬆️
neon_http_client	96.69% <ø> (ø)		Carriedforward from c07d612
neon_notifications	100.00% <ø> (ø)		Carriedforward from c07d612
neon_talk	99.45% <ø> (ø)		Carriedforward from c07d612
nextcloud	25.90% <ø> (ø)		Carriedforward from c07d612
notifications_app	100.00% <ø> (ø)
sort_box	90.90% <ø> (ø)		Carriedforward from c07d612
talk_app	99.09% <ø> (ø)

*This pull request uses carry forward flags. Click here to find out more.

Files with missing lines	Coverage Δ
...neon_framework/lib/src/login/bloc/login_event.dart	100.00% <100.00%> (ø)
...neon_framework/lib/src/login/bloc/login_state.dart	100.00% <100.00%> (ø)
...n_check_account/bloc/login_check_account_bloc.dart	100.00% <100.00%> (ø)
..._check_account/bloc/login_check_account_event.dart	100.00% <100.00%> (ø)
..._check_account/bloc/login_check_account_state.dart	100.00% <100.00%> (ø)
...n_check_account/view/login_check_account_page.dart	100.00% <100.00%> (ø)
...gin_check_server/bloc/login_check_server_bloc.dart	100.00% <100.00%> (ø)
...in_check_server/bloc/login_check_server_event.dart	100.00% <100.00%> (ø)
...in_check_server/bloc/login_check_server_state.dart	100.00% <100.00%> (ø)
...gin_check_server/view/login_check_server_page.dart	100.00% <100.00%> (ø)
... and 25 more

... and 8 files with indirect coverage changes

[provokateurin]

I haven't tested it myself yet, but it looks very promising.
I have to agree this is a very clean approach for separation of concerns and seems fairly scalable.

[provokateurin]

I didn't read through every change, but I'll trust you that it's good.
I only found two minor things that you might want to fix.

[provokateurin]

Really awesome work btw ❤️