LT-21205: Features should obey the order set in Feature Types

[jtmaxwell3]

This fixes https://jira.sil.org/browse/LT-21205 by changing LongName to sort features based on the order in the type with any remaining features sorted alphabetically afterwards. I also made LongNameSorted use the same code as LongName.

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This change is 

[github-actions]

LCM Tests

    8 files   -     8      8 suites   - 8   1m 45s ⏱️ - 1m 8s
2 830 tests ±    0  2 787 ✅  -    23  43 💤 +23  0 ❌ ±0 
5 634 runs   - 5 634  5 548 ✅  - 5 541  86 💤  - 93  0 ❌ ±0 

Results for commit 6605851. ± Comparison against base commit d0d49ca.

This pull request skips 23 tests.

SIL.LCModel.Utils.FileUtilsTest ‑ ActualFilePath_DirectoryNameComposedFilenameExistsWithDifferentCase_Linux
SIL.LCModel.Utils.FileUtilsTest ‑ ActualFilePath_DirectoryNameDecomposedFilenameExistsWithDifferentCase_Linux
SIL.LCModel.Utils.FileUtilsTest ‑ ActualFilePath_DirectoryNameExactMatchFilenameExistsWithDifferentCase_Linux
SIL.LCModel.Utils.FileUtilsTest ‑ ChangeLinuxPathIfWindows_inLinux_unchanged
SIL.LCModel.Utils.FileUtilsTest ‑ ChangeWindowsPathIfLinuxPreservingPrefix_doesNotStartWithPrefixAndHasLowercaseDrive_works
SIL.LCModel.Utils.FileUtilsTest ‑ ChangeWindowsPathIfLinuxPreservingPrefix_lowercaseDrive_works
SIL.LCModel.Utils.FileUtilsTest ‑ ChangeWindowsPathIfLinux_DoubleDriveLetters_changed
SIL.LCModel.Utils.FileUtilsTest ‑ ChangeWindowsPathIfLinux_OneBackslash_changed
SIL.LCModel.Utils.FileUtilsTest ‑ ChangeWindowsPathIfLinux_arbitraryDrive_error
SIL.LCModel.Utils.FileUtilsTest ‑ ChangeWindowsPathIfLinux_driveOnlyLowercase_changed
…

[hahn-kev]

I'm not sure when exactly this would get hit, but it will mean this spec will be sorted to the front, and if there's more than one spec with a null RA then they will not be consistently ordered. I'd either have a fallback ordering or return something like "2"+spec.Guid to ensure that they're always ordered consistently.