Remove smwgContLang

[mwjames]

This PR is made in reference to: #1848, #1896, #1941

This PR addresses or contains:

• Removes smwgContLang which was never a configuration setting but got used this way, we have removed any reference of it in SMW with (Move internationalization from languages to i18n #1896, Remove $smwgContLang usage #1941) and now it is time to remove remaining references from the code base
• If for some reason some external user made use of it then the smwfContLang() function is provided as convenience

This PR includes:

• Tests (unit/integration)
• CI build passed

[mwjames]

@kghbln Could be that PF is relying on that but honestly that isn't any of my concern since SMW isn't using it since at least 2.5 and it should have never been a $GLOBALS in the first place. Anyway, out of compliance I added smwfContLang() which they can rely upon if the necessity arises.

With this PR all settings parameters in the Settings object are stateless and can now be easily serialized.

[kghbln]

How can I find out? When I do a code search I get no results for any extensions but SMW. In the end I would like to create a somewhat decent error report.

[mwjames]

How can I find out? When I do a code search I get n

You searched for the wrong term, using smwgContLang instead of smwfContLang because smwfContLang() is a function I introduced with this PR.

https://codesearch.wmflabs.org/extensions/?q=smwgContLang&i=nope&files=&repos=

[kghbln]

You searched for the wrong term, using smwgContLang instead of smwfContLang because smwfContLang() is a function I introduced with this PR.

Thanks for the info. Three extensions affected and information provided:

• Page Forms / T246579
• Semantic Drilldown / T246581
• Semantic Internal Objects / T246582

[mwjames]

@kghbln FYI https://phabricator.wikimedia.org/T249172 is the consequence of this change because $smwgContLang no longer exists as explained above.

	$datatypeLabels = $smwgContLang->getDatatypeLabels();

[kghbln]

Thanks for the note. I cross-referenced the two issues.