Add `escape-alias` multimethod to `sql.qp` to handle translating an alias (whether for a field or expression) into something supported by the driver in quesion

Add default impl that is essentially identity

Marking `sql.qp/field->alias` as deprecated, and changing its default implementation to invoke the new `sql.qp/escape-alias` on the field's `:name` (with the intention of removing it in a future release, since individual driver won't need to override this, so much as they'll need to override `escape-alias` itself).

Override `sql.qp/escape-alias` method for both BigQuery drivers to run through the same `->valid-field-identifier` function already defined for this purpose

Add test for a custom expression with weird characters

Closes #18168.

* Create `postgres-12` snapshot

* Use `postgres-12` snapshot in tests

* Relocate postgres `add` spec

* Relocate postgres `sandboxes` spec

* Relocate postgres `native` spec

This actually didn't have anything to do with the native questions.
We simply used native editor because it was easier to reproduce the issue.

* Relocate postgres `permissions` spec

* Relocate postgres `query` spec

* Relocate postgres `custom-column` spec

* Remove postgres from `metabase-db`

There is a problem when there are no card ids for a userland query (so not all userland queries are non-adhoc queries: they can be adhoc), where viewlog needs a card id so it chokes. Just adds a check so it doesn't even try to emit a viewlog, since the auditing is for non-adhoc queries only.

Check feature flag on backend /graph PUT API for block permission

Check for the `:advanced-permissions` flag in `update-db-permissions!`, when a `:schemas` `:block` entry is present in the graph

Set feature flag in tests when using API

Add new test to ensure failure in the case that feature flag is missing

* Set the timeout to 2s because of Mongo

* Minor async require cleanup

* Sort namespaces

Overall purpose of PR is to add row drill-ins to the tools to fix broken questions, so you can take a look-see into what the broken questions are.

A tiny nit thing wasn't caught by CI and broke master. This was because there's a CI cache. I can confirm that this didn't hit the CI cache and the other thing that broke isn't breaking anymore

- `TEXT` in Redshift is equivalent to `VARCHAR(256)`, use
  `VARCHAR(1024)` instead
- Unskip all tests skipped on Redshift due to sample dataset issue
- Add explicit `:order-by` to `join-source-queries-with-joins-test`
  to make it pass in Redshift as Redshift does not preserve order
  after join (like a lot of other distributed query engines)
- Add `VACUUM` and `ANALYZE` call after INSERT to improve performance

from maz in slack:
Should not remove verification:
 - Moving to another collection
 - Pinning/unpinning
 - Adding/removing an alert on the question
 - Turning sharing on the question on/off
Should remove verification:
 - Editing the query
 - Editing the visualization or viz settings
 - Editing the title or description

This really just identifies when not to remove verification, otherwise
does remove verification. Alerts are not related to questions through
the api so no worries there. Everything else is just excluding
attributes from the diff calculation.

In tests, went perhaps a bit haywire with the macrolet, allowing to
define macros inline rather than farther away from the call site. Used
twice:
- once to optionally add in moderation review into the with-temp. This
macro is handy to ensure we always have a fresh state of card and don't
have leftover changes or verifications. Has to be a macro since i want
to dynamically change whether there are verifications in the with-temp*
vector binding
- a way to more easily reduce repetition when asserting something is
verified, do an action, and assert it is still verified

Cache controls all landed but is lacking in the audit capacity wanted for in the notion doc. This PR adds that audit capability and by the by changes the ViewLog model in order to be able to deliver on the question of whether ViewLogs were cache hits or not.

This reverts commit f94510a3.

* Do not change display on drill down to questions

* unskip repro

* include displayIsLocked explicitly otherwise it breaks almost the entire app

Details page for tools to fix broken questions. Also the PR ran long enough that nemanja found some bugs in the details page. Does not include any loading overlay or anything to indicate that reloads are happening, which is for 41.1 I guess

 Fix BigQuery Percentile and Median expressions not using correct backtick quoting

Ensure the identifier components are quoted by reifying `ToSql` for the `APPROX_QUANTILES` expression

Add test to ensure query is created properly

Mark `:percentile-aggregations` as being supported in the new driver

This reverts commit 46c76c95.