Override the target language in the parser options, so that it isn’t
looked up from the database; this lets UriLibraryTest avoid database
access. And since the Database group is no longer strictly required,
remove the statement to that effect from the phpdoc again.
Bug: T345372
Change-Id: I79f35257b123eb939d9ab67b16aa56d34586bb67
mw.loadData() allows for optimizing the loading Lua tables by requiring
only one parse and lookup. However it's often easier for people to
write/maintain bulk data in JSON rather than Lua tables.
mw.loadJsonData() has roughly the same characteristics as mw.loadData()
and it can be used on JSON content model pages in any namespace.
As noted on the linked bug report, it's possible to already implement
this by writing a wrapper Lua module that loads and parses the JSON
content. But that requires a dummy module for each JSON page, which is
just annoying and inconvenient.
Test cases are copied from the mw.loadData() ones, with a few omissions
for syntax not supported in JSON (e.g. NaN, infinity, etc.).
Bug: T217500
Change-Id: I1b35ad27a37b94064707bb8c9b7108c7078ed4d1