LT-22517: Word Export: Add between text to variant types

[mark-sil]

This change is 

[github-actions]

NUnit Tests

    1 files  ±0      1 suites  ±0   10m 51s ⏱️ -47s
4 208 tests +2  4 138 ✅ +2  70 💤 ±0  0 ❌ ±0 
4 217 runs  +2  4 147 ✅ +2  70 💤 ±0  0 ❌ ±0 

Results for commit 222d13d. ± Comparison against base commit dc4ed22.

This pull request removes 2 and adds 4 tests. Note that renamed tests count towards both.

SIL.FieldWorks.XWorks.LcmWordGeneratorTests ‑ GenerateBeforeBetweenAfterContent
SIL.FieldWorks.XWorks.LcmWordGeneratorTests ‑ GenerateBeforeBetweenAfterContentWithWSAbbreviation

SIL.FieldWorks.XWorks.LcmWordGeneratorTests ‑ BeforeBetweenAfterContent
SIL.FieldWorks.XWorks.LcmWordGeneratorTests ‑ BeforeBetweenAfterContentWithWSAbbreviation
SIL.FieldWorks.XWorks.LcmWordGeneratorTests ‑ BetweenContentAbsentForSingleVariantTypeGroup
SIL.FieldWorks.XWorks.LcmWordGeneratorTests ‑ BetweenContentOnceForMultipleVariantTypesGroups