Extend MergeMessageVersionStrategy to support squash commits

[DSpirit]

Extended the TryParse operation to include a regex check whether the commit message contains one of the specified CommitMessageFormats in order to support increment of merges from release into main branch when a squash merge has been applied.

Motivation and Context

Discussion

How Has This Been Tested?

• Local tests with only one merge commit worked
• Extended the MergeMessageBaseVersionStrategyTests.cs with a test using the false flag on IsMergeCommit

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.

[asbjornu]

This was less code than I expected. If the tests pass, I give this a 👍🏼.

[asbjornu]

Can we expose this as Commit.HasMergeMessage(…) instead?

Suggested change

	if (mergeCommit.IsMergeCommit || mergeMessageFormats.Any(format => format.Pattern.IsMatch(mergeCommit.Message)))
	if (mergeCommit.IsMergeCommit || mergeCommit.HasMergeMessage(mergeMessageFormats))