[6.x] Use qualified column names in pivot query

[vdlp-mw]

Use qualified column names in pivot query. This allows a user to extend the query with a join that may include ambiguous column names.

Old extended query example:

# SQLSTATE[23000]: Integrity constraint violation: 1052
# Column 'rule_id' in WHERE clause is ambiguous

SELECT `cmp_rule`.*
FROM   `cmp_rule`
       RIGHT JOIN `reg_rule`
               ON `reg_rule`.`rule_id` = `cmp_rule`.`rule_id`
WHERE  `base_id` = 1
       AND `rule_id` IN ( 5 ) 

New extended query example:

SELECT `cmp_rule`.*
FROM   `cmp_rule`
       RIGHT JOIN `reg_rule`
               ON `reg_rule`.`rule_id` = `cmp_rule`.`rule_id`
WHERE  `cmp_rule`.`base_id` = 1
       AND `cmp_rule`.`rule_id` IN ( 5 ) 

I also created a issue for this PR here: #36718

[vdlp-mw]

Two similar PRs that also introduce the usage of qualified columns that may be worth looking into.
PR: Fix ambiguous UPDATED_AT columns #26031
PR: Fix qualified column in withAggregate #35061

[driesvints]

Can you also try this on PostgreSQL? Seems like one of the linked prs was reverted because it didn't work on that.

[vdlp-mw]

I've re-ran the tests with the pgsql driver and all tests are still passing. Some modifications to the docker-composer.yaml and test.sh files were needed to test with postgresql. You can find the changes in here: vdlp-mw@e0b7a7b or on this branch vdlp-mw/framework@qualified-foreign-pivot-keyname-pgsql-test.

For some odd reason some unrelated tests hanged after switching the database driver. I've re-ran the tests with the following command:

$ ./bin/test.sh --filter '/(Illuminate\\Tests\\Database\\DatabaseEloquentMorphToManyTest)/'
Creating network "framework_default" with the default driver
Creating framework_redis_1     ... done
Creating postgres              ... done
Creating framework_memcached_1 ... done
Waiting for services to boot   ...
PHPUnit 9.5.4 by Sebastian Bergmann and contributors.

Runtime:       PHP 7.4.16
Configuration: /data/phpunit.xml.dist

....                                                                4 / 4 (100%)

I also re-ran the tests with the following filter with no reported issues:
./bin/test.sh --filter '/(Illuminate\\Tests\\Database)/'.