Fixes a number of bugs, including issue #55

[dylon]

Changes:

• Addresses issue Lookup symbols across modules does not work #55 by jumping to symbol definitions in external documents.
• Resolves the canonical paths of includes.
• Corrects off-by-one errors on changes to the line numbers from lfortran.
• Adds support for matching completions against all symbols in the document.
• Corrects the completion kinds by mapping them from type SymbolKind to type CompletionItemKind.
• Corrects the mtime type of FileCacheEntry to Date; resolves file paths while extracting definitions.
• Corrects highlighting and query extraction logic by matching against type strings in additional to symbol literals.
• Depends on lfortran when extracting hover previews.
• Removes LFortranLanguageServer.renameSymbol since it has been deprecated and replaced with the analogous method of LFortranCLIAccessor.
• Corrects unit and integration tests for latest changes.

To understand the changes to text highlighting and query extraction, consider global.f90 from the SNAP repo:

!-----------------------------------------------------------------------
!
! MODULE: global_module
!> @brief
!> Global variables for data types, file names and unit numbers, and
!> commonly used numbers
!
!-----------------------------------------------------------------------

MODULE global_module

  IMPLICIT NONE

  PUBLIC

  SAVE
!_______________________________________________________________________
!
! Numerical kinds.
!_______________________________________________________________________

  INTEGER, PARAMETER :: l_knd = KIND( .TRUE. )
  INTEGER, PARAMETER :: i_knd = SELECTED_INT_KIND( 8 )
  INTEGER, PARAMETER :: r_knd = SELECTED_REAL_KIND( 13 )
!_______________________________________________________________________
!
! File names and unit numbers.
!
! ifile       - input file name
! iunit       - input file unit number
! ofile       - output file name
! ounit       - output file unit number
!_______________________________________________________________________

  CHARACTER(LEN=64) :: ifile, ofile

  INTEGER(i_knd), PARAMETER :: iunit=10, ounit=11
!_______________________________________________________________________
!
! Commonly used numbers.
!_______________________________________________________________________

  REAL(r_knd), PARAMETER :: zero = 0.0_r_knd
  REAL(r_knd), PARAMETER :: half = 0.5_r_knd
  REAL(r_knd), PARAMETER :: one  = 1.0_r_knd
  REAL(r_knd), PARAMETER :: two  = 2.0_r_knd

  REAL(r_knd), PARAMETER :: pi = 3.14159265358979_r_knd
!_______________________________________________________________________
!_______________________________________________________________________


END MODULE global_module

When the cursor hovers over r_kind, all instances of r_kind should be highlighted, including those representing REAL type suffixes:

[certik]

I think that looks good, thanks for fixing the bugs!

[certik]

I had to resolve some conflicts. Hopefully I did it correctly. If not, you can fix it in subsequent PRs.

[certik]

@dylon the CI fails. Let's get this fixed and merged.

We need to do another round of bug hunting. We fixed a lot of things in LFortran, but there might be more issues.

[dylon]

The integration test keeps hitting a timeout while awaiting a DOM state change. I cannot reproduce this locally. I will update the dependencies and try again.