Drop net461 support in favor of net462 and drop net6.0

[jasonleenaylor]

• Update to latest libpalaso and L10nSharp

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This change is 

[github-actions]

Test Results

     10 files  +    6     453 suites  +41   2h 45m 51s ⏱️ -1s
   989 tests +106     913 ✔️ +  53    56 💤 +33  20 ❌ +20 
4 258 runs  +218  4 013 ✔️ +107  200 💤 +66  45 ❌ +45 

For more details on these failures, see this check.

Results for commit 18e435f. ± Comparison against base commit 15f8823.

♻️ This comment has been updated with latest results.

[rmunn]

Testing locally on Linux, I get the following error when running ChorusMerge.Tests: You must create at least one LocalizationManager before trying to localize any strings.

That happens on the Main_NoConflictFileB4_ConflictsEncountered_HaveConflictFileAfter and Main_Utf8FilePaths_FileNamesOk tests.

Stack trace:

ChorusMerge Error: You must create at least one LocalizationManager before trying to localize any strings.
    at L10NSharp.LocalizationManagerInternal`1.GetStringFromAnyLocalizationManager(String stringId)
    at L10NSharp.LocalizationManagerInternal`1.GetString(String stringId, String englishText, String comment, String englishToolTipText, String englishShortcutKey, IComponent component)
    at L10NSharp.LocalizationManagerInternal`1.GetString(String stringId, String englishText, String comment)
    at L10NSharp.LocalizationManager.GetString(String stringId, String englishText, String comment)
    at Chorus.merge.xml.generic.Conflict.get_KeptChangePattern() in .../chorus/src/LibChorus/merge/xml/generic/Conflict.cs:line 126
    at Chorus.merge.xml.generic.Conflict.AppendWhatHappened(StringBuilder sb) in .../chorus/src/LibChorus/merge/xml/generic/Conflict.cs:line 248
    at Chorus.merge.xml.generic.Conflict.MakeHtmlDetails(XmlNode oursContext, XmlNode theirsContext, XmlNode ancestorContext, IGenerateHtmlContext htmlMaker) in .../chorus/src/LibChorus/merge/xml/generic/Conflict.cs:line 231
    at Chorus.merge.xml.generic.XmlMergeService.AddConflictToListener(IMergeEventListener listener, IConflict conflict, XmlNode oursContext, XmlNode theirsContext, XmlNode ancestorContext, IGenerateHtmlContext htmlContextGenerator, XmlMerger merger, XmlNode nodeToFi
ndGeneratorFrom) in .../chorus/src/LibChorus/merge/xml/generic/XmlMergeService.cs:line 64
    at Chorus.merge.xml.generic.XmlMergeService.AddConflictToListener(IMergeEventListener listener, IConflict conflict, XmlNode oursContext, XmlNode theirsContext, XmlNode ancestorContext, IGenerateHtmlContext htmlContextGenerator) in .../chorus/
src/LibChorus/merge/xml/generic/XmlMergeService.cs:line 45
    at Chorus.merge.xml.generic.XmlMergeService.AddConflictToListener(IMergeEventListener listener, IConflict conflict, XmlNode oursContext, XmlNode theirsContext, XmlNode ancestorContext) in .../chorus/src/LibChorus/merge/xml/generic/XmlMergeSer
vice.cs:line 35
    at Chorus.merge.xml.generic.XmlMergeService.AddConflictToListener(IMergeEventListener listener, IConflict conflict) in .../chorus/src/LibChorus/merge/xml/generic/XmlMergeService.cs:line 26
    at Chorus.FileTypeHandlers.DefaultFileTypeHandler.Do3WayMerge(MergeOrder mergeOrder) in .../chorus/src/LibChorus/FileTypeHandlers/DefaultFileTypeHandler.cs:line 47
    at ChorusMerge.Program.Main(String[] args) in .../chorus/src/ChorusMerge/Program.cs:line 61

This happens both on net462 and also, if I update the TargetFrameworks in ChorusMerge.Tests.csproj, on net8.0.

[rmunn]

Since #354 just updated to drop net6.0 support, I'll merge this into #354 as well. That way once this is ready, if #354 has already been merged then there won't be too many merge conflicts, hopefully none in fact.

[jasonleenaylor]

@rmunn Hmm, I created this as a draft so as not to encourage premature engagement. I just closed it since I had redone most of the work locally after rebasing onto your effort.