Switch off migrated reports before next crux/crawl completion

[max-ostapenko]

Renamed and moved multiple SQL files from sql/ to migrated_sql/.

To merge after HTTPArchive/dataform#141.

[max-ostapenko]

@tunetheweb please have a look.
I'm not done with migration, but once ready - we'll switch some reports off.

[tunetheweb]

LGTM

But, given that we've already had problems with this month's crawl, let's run the known way one more time and switch over for September.

[max-ostapenko]

@tunetheweb please let me know the concerns. I don't understand an issue migrating this month.
And actually wanted to switch histogram reports today (as don't need retrospective data to append to).

[tunetheweb]

No real concerns. Just we're running late this month so didn't really wanna add any more change in case this goes wrong too. But not a biggy if you have reason to want to do this now.

Also can you copy the sql/.sqlfluff file to migrated_sql folder so linting still works? Though hopefully, as you say, this will all be gone soon...