UGC-4233 - Fixed multitude of problems with UsingData

[Michal-Chatlas1221]

During upgrade to 1.39 we did a major refactor of the extension, and it broke in multiple ways:

• https://fandom.atlassian.net/browse/UGC-4234
• https://fandom.atlassian.net/browse/UGC-4232
• https://fandom.atlassian.net/browse/UGC-4233
• https://fandom.atlassian.net/browse/UGC-4236
• https://fandom.atlassian.net/browse/UGC-4131

After spending some time trying to pinpoint the root causes and fix those problems I've decided to instead revert the codebase to it's pre-upgrade state and fix issues starting there, which proved significantly easier.

the diff that handles this part is folowing: a3f162e

[mszabo-wikia]

Would be good to get the CI working (asking someone with admin perms to enable it?), it seems the current parser tests pass on this branch:

This is MediaWiki version 1.41.0-alpha (cc1bb28).

Running parser tests from "extensions/UsingData/tests/parser/parserTests.txt"...
Running test #data parser function [legacy]... PASSED
Running test #using parser function [legacy]... PASSED
Running test #using parser function with parameter override [legacy]... PASSED
Running test #using parser function with template override [legacy]... PASSED
Running test #using parser tag [legacy]... PASSED
Running test transcluded #using parser tag [legacy]... PASSED

Passed 6 of 6 tests (100%)... ALL TESTS PASSED!

Maybe we can add some more test cases that would have failed before?

[Michal-Chatlas1221]

Would be good to get the CI working (asking someone with admin perms to enable it?), it seems the current parser tests pass on this branch:

This is MediaWiki version 1.41.0-alpha (cc1bb28).

Running parser tests from "extensions/UsingData/tests/parser/parserTests.txt"...
Running test #data parser function [legacy]... PASSED
Running test #using parser function [legacy]... PASSED
Running test #using parser function with parameter override [legacy]... PASSED
Running test #using parser function with template override [legacy]... PASSED
Running test #using parser tag [legacy]... PASSED
Running test transcluded #using parser tag [legacy]... PASSED

Passed 6 of 6 tests (100%)... ALL TESTS PASSED!

Maybe we can add some more test cases that would have failed before?

Apparently I'm the admin, so I'll see what I can do