Fix GC-MS Fiehn RI Console compatibility

[htsugawa]

Summary

• accept colon and equals syntax, quoted values, and GUI/legacy GC-MS field aliases
• resolve GC-MS library and RI dictionary paths relative to the method/mapping files
• preserve path casing while parsing enum values case-insensitively
• fail early with actionable MSP and RI dictionary diagnostics
• report loaded GC-MS library and retention matching settings

Validation

• dotnet test tests/MSDIAL5/MsdialCoreTestAppTests/MsdialCoreTestAppTests.csproj -c Release
• Passed: 9, Failed: 0
• Release Console build completed successfully
• existing dependency and architecture warnings remain unchanged