Fix REASSIGN OWNED BY for background jobs

[mkindahl]

Using REASSIGN OWNED BY for background jobs do not work because it does not change the owner of the job. This commit fixes this by capturing the utility command and makes the necessary changes to the bgw_job table.

It also factors out background jobs DDL tests into a separate file.

[codecov]

Codecov Report

Attention: Patch coverage is 85.18519% with 4 lines in your changes missing coverage. Please review.

Project coverage is 81.77%. Comparing base (59f50f2) to head (01acf14).
Report is 272 commits behind head on main.

Files	Patch %	Lines
src/process_utility.c	85.18%	1 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6987      +/-   ##
==========================================
+ Coverage   80.06%   81.77%   +1.70%     
==========================================
  Files         190      203      +13     
  Lines       37181    38002     +821     
  Branches     9450     9851     +401     
==========================================
+ Hits        29770    31075    +1305     
+ Misses       2997     2967      -30     
+ Partials     4414     3960     -454     

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[svenklemm]

Please add a test for reassigning to postgres.

[mkindahl]

Please add a test for reassigning to postgres.

I assume you mean a user with SUPERUSER privileges: we do not have the "postgres" user in the test suite.

[mkindahl]

Please add a test for reassigning to postgres.

I updated it with a test that demonstrates that assigning the job to a different owner does not work unless you've got superuser privileges.

Don't think this is how we want it to work since an administrator should be able to reassign jobs without having superuser privileges.

[svenklemm]

Please add a test for reassigning to postgres.

I updated it with a test that assigning the job to a different owner does not work unless you've got superuser privileges.

Don't think this is how we want it to work since an administrator should be able to reassign jobs without having superuser privileges.

I wanted to see that it doesnt work, anything else would be a security vulnerability.

[mkindahl]

Please add a test for reassigning to postgres.

I updated it with a test that assigning the job to a different owner does not work unless you've got superuser privileges.
Don't think this is how we want it to work since an administrator should be able to reassign jobs without having superuser privileges.

I wanted to see that it doesnt work, anything else would be a security vulnerability.

Yes, obviously, but in this form it is also a usability issue.

I am not sure how to have some sort of administrative user that does not have "superuser" privileges but still can run a "reassigned owned by" in a limited fashion. Not even sure it is possible to define a "safe" rule for this. Something we need to think about.

[fabriziomello]

Since we're using it in other suite tests as well what about move it to utils/testsupport.sql?

[mkindahl]

Since we're using it in other suite tests as well what about move it to utils/testsupport.sql?

It makes sense but since this is just copied from the other BGW tests it would be sensible to take it as a separate refactoring PR and fix the other uses as well.