Add advisory_lock utility from AWX

[AlanCoding]

This migrates advisory_lock from AWX to DAB. This is similar in spirit to #660

Importantly, I went the route of not adding a new dependency, because there was only a single method from the library we were using, and I'm pretty confident that the MIT license lets you do whatever you want. In doing this, I deleted the use of six for python2 compatibility which further reduced the complexity of the code I ported.

Additionally requested reviewers @Alex-Izquierdo @TheRealHaoLiu

[john-westcott-iv]

It might be nice to have vendor specific files in ansible_base/lib/utils/db i.e. something for postgres/mssql/sqlite and then the db.py would have "Generic methods" which would check the vendor and then call items from the DB specific files.

[AlanCoding]

It might be nice to have vendor specific files in ansible_base/lib/utils/db i.e. something for postgres/mssql/sqlite

Maybe sometime, I just don't feel like we're really there yet. AWX has probably the most postgres-specific code, and it's just lying around scatter-shot.

It might be nice to attempt sqlite solution, probably like this:

https://stackoverflow.com/questions/6931342/system-wide-mutex-in-python-on-linux

class Locker:
    def __enter__ (self):
        self.fp = open("./lockfile.lck")
        fcntl.flock(self.fp.fileno(), fcntl.LOCK_EX)

    def __exit__ (self, _type, value, tb):
        fcntl.flock(self.fp.fileno(), fcntl.LOCK_UN)
        self.fp.close()

Then that would share a lot of feature and not share a lot of features. So then you have a lot of param handling logic to error if it's 1 vendor and not another. Definitely going in the opposite direction of django-pglocks where this comes from. And I do think that would be good for when we introduce a sqlite version, but that just seems too arbitrary and premature until we're at that point.

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
81.6% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[chrismeyersfsu]

I'll mention a real-world issue I've had.

We had a lock that was held and not let go. Which lock? That was hard to find out. It was easy enough to surface the set of held locks from Postgres. The hard part was taking the integer (lock_id in this code I think) --> lock name as a string.