Optimize full-text to selectively rebuild

[Hydrocharged]

This changes the Full-Text rebuild process to only trigger on tables that were changed in both roots (ours and theirs), rather than rebuilding every time a merge is performed regardless of what was actually changed. The rules here are fairly permissive, in that if a parent table or any of the indexed child tables are changed in both, then we rebuild all Full-Text indexes for that table. I chose this behavior out of caution, as dual changes in a single child table is probably due to some kind of renaming, so it's safer to rebuild everything for that table.

[coffeegoddd]

@Hydrocharged DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
d36505d	ok	5937457

version	total_tests
d36505d	5937457

correctness_percentage
100.0

[timsehn]

This change still causes mediawiki to hang if:

1. An import job is running changing a table named searchindex with fulltext indexes
   -AND-
2. You hit the website updating the objectcache and job tables which do not have fulltext indexes

Is that behavior intended?

[Hydrocharged]

PR has been reworked to address the problem as described. I replicated the issue on the mediawiki dataset, and tested this PR's branch to confirm that it resolves the issue.

[coffeegoddd]

@Hydrocharged DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
ee736b0	ok	5937457

version	total_tests
ee736b0	5937457

correctness_percentage
100.0

[timsehn]

I tested this and it now works to import a dump and browse MediaWiki at the same time.

[reltuk]

LGTM! I opened a PR against this branch with some suggested simple refactorings (move things into functions) and some comments which made things clearer to me. Feel free to take it or leave it!

#7617

[coffeegoddd]

@Hydrocharged DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
dcb2c7d	ok	5937457

version	total_tests
dcb2c7d	5937457

correctness_percentage
100.0