Add checks to prevent inaccuracies in POT files

[dhruvkb]

Problem

Changes to the translation strings and the en.json5 to POT file pipeline can have drastic consequences but those PRs have no specific checks for this POT change associated with them. Once merged, they will irreversibly overwrite the POT file, leading to problems for translators.

Description

If a PR affects the POT file, the diff in the POT should be commented on the PR so that unforeseen negative consequences can be avoided. These checks are similar to the bundle size checks that are run on the frontend PR.

Alternatives

Alternatively, any PR that modifies the en.json5 to POT file pipeline should not be allowed to write to the translation branch but rather make a PR so that the POT changes can be analysed and merged only if correct.

Additional context

This issue came up in a comment WordPress/openverse-frontend#2161 (comment) on PR WordPress/openverse-frontend#2161 which fixes translation issue WordPress/openverse-frontend#2159 as a solution to @krysal's review comment WordPress/openverse-frontend#2161 (review). Alternative approaches welcome.

[krysal]

I assume by "inaccuracies" here you mean more like big shift in the POT file, am I right?

Thank you for opening this issue. I think it deserves a higher priority than the lowest.

[dhruvkb]

@krysal haha yes, but by "inaccuracies" I meant we should also be able to catch even smaller shifts.