Add -Xgc options to enable/disable Estimate Fragmentation

**Issue or pull request number:**
https://github.com/eclipse-openj9/openj9/pull/22321

**Overview:**
-Xgc:enableEstimateFragmentation and -Xgc:disableEstimateFragmentation options have been added.

**Release target:**
0.55

**Applies to the following JDK versions:**
All

**Applies to the following platforms:**
All

**For new command line options:**
- Purpose:
- Restrictions:
