Validate the config page with JsonValidateSave and track maps on SMW's parser

[JeroenDeDauw]

Follows-up to #948

MediaWiki 1.46 deprecates the EditFilter hook, and Maps registers it during setup, so every request logs a deprecation
warning. MediaWiki master (1.47) no longer runs it, so the MediaWiki:Maps config page accepts invalid configuration
there, contrary to the 15.0.0 release note. Validation now uses JsonValidateSave, whose interface is the same from
1.43 through master. Core runs it on every save of JSON content through PageUpdater, such as by edit.php or a
rollback, and on undeletion. Each validation error is its own fatal message and the maps-config-invalid heading is
gone, so the edit API's default error format reports the first validation error instead of hookaborted. On 1.43 to
1.46 the edit form lists the errors in one box and core escapes their parameters; master's edit form parses error
parameters as wikitext, for every extension.

With $egMapsEnableCategory enabled, the map result format read the main parser's output to decide whether to add the
tracking category. When the main parser had not parsed anything yet, as on Special:Ask or when Parsoid renders the page,
that logged a deprecation warning on 1.43 to 1.45 and was a fatal error on 1.46 and master; after an earlier parse, the
category went to that parse's output and was lost. The category is now added only for inline queries, to the parser that
SMW runs the query with, once that parser has parsed something. For #ask and #show that is the parser running the
parser function. So pages that Parsoid renders, as master's RefreshLinksJob does by default, now get the category, and
so do pages whose wikitext another extension, such as NativeMarkdown, parses on its own parser. Semantic Compound
Queries and other callers get whichever parser SMW last held, which can be idle after an earlier query; the category
then goes to that query's output and is lost.

Considered, omitted:

• EditFilterMergedContent: core runs it only for the edit form and API, content model changes and MCR undo
• Escaping the error parameters in Maps: on 1.43 to 1.46, where core escapes them, they would show escaped twice
• Validating moves onto MediaWiki:Maps (MovePageIsValidMove) and imports (no hook): Maps ignores invalid values
  when it reads the page
• SMW's parser for popup wikitext too (getParserClone()): the clone runs a parse of its own, so it does not hit this
  error; it only resolves popup links against an unrelated page
• The tracking category for a query whose results have no coordinates: Maps still adds it before checking for
  coordinates

_{AI-authored — Claude Code, Opus 5.5 (max); detailed spec from @JeroenDeDauw, redesigned once on orchestrator review feedback; diff not yet human-reviewed; regression tests failed on local MediaWiki 1.43 with SMW 7 before the fixes, PHPUnit, phpcs and PHPStan pass locally, edit form, edit API, edit.php and a Parsoid render checked on 1.43, CI green including the SMW 6 and SMW 7 jobs; 1.46 and master checked against core source only.}