[Transport] Add option cleanup

[sybrew]

For Transport, add a checkbox to clean the options of an SEO plugin.

Cleaning the options should also deactivate the SEO plugin (and related plugins, like Pro versions or add-ons).
This is necessary to prevent automatic repopulation of the options and further annoyances, such as the setup wizard.

[sybrew]

From Vladimir's comment:

Sybre wrote: TSF cleans up all transported data of Rank Math, so your database is squeaky clean right after transporting.

it’s in vain! It turns out that if a person just wants to see how your plugin works, try it, then you erase the database for him!

This is sabotage!

if a person has not made a backup copy before the transfer, then he will lose part of the site data!

I agree. We should not rewrite or automatically clean up the data but only copy every data point instead.
Then, only delete the old data if the user so chooses via a checkbox.

This might be tricky when the meta keys match -- but this is only an issue with Genesis (from which we copied the keys).

An edge case we might face is when there's no more disk space. However, this is rare and solvable by the user manually -- on failure, the logger should report there's no writable disk space, though I might want to test that and add it to the FAQ (just in case).