Update audit event messages for merge request approval settings

Problem to solve

As the merge request approval settings have updated their descriptions, Audit Event actions need to be updated to keep consistent messaging.

If prevent approvals by users who add commits is enabled/disabled, then it will read changed prevent merge request approval from reviewers from false to true or vice-versa.

Proposal

We could start by just adjusting the one message for the committer setting (completed in !72623 (merged))

Changed prevent merge request approval from reviewers committers from...

However, the whole lot of them could be refreshed to be more readable. These will be followed up in #342094 (closed)

Merge request approval settings

Current	Proposal
Changed prevent merge request approval from authors from false to true	Enabled preventing merge request approval from authors
Changed prevent merge request approval from authors from true to false	Disabled preventing merge request approval from authors
Changed prevent merge request approval from reviewers from false to true	Enabled preventing merge request approval from committers
Changed prevent merge request approval from reviewers from true to false	Disabled preventing merge request approval from committers
Changed prevent users from modifying MR approval rules in merge requests from false to true	Enabled preventing users from modifying merge request approval rules in merge requests
Changed prevent users from modifying MR approval rules in merge requests from true to false	Disabled preventing users from modifying merge request approval rules in merge requests
Changed require user password for approvals from false to true	Enabled requiring user password for merge request approvals
Changed require user password for approvals from true to false	Disabled requiring user password for merge request approvals
Changed require new approvals when new commits are added to an MR from false to true	Enabled removing all approvals when commits are added to the source branch
Changed require new approvals when new commits are added to an MR from true to false	Disabled removing all approvals when commits are added to the source branch