pages with invalid properties

Define "invalid properties"

@jeroen e.g. a mismatch of commons media data type (value) with a wikibase entity id property

which apparently can happen per bug 62425 (and perhaps other ways)

can happen per

https://bugzilla.wikimedia.org/show_bug.cgi?id=61913 and
https://bugzilla.wikimedia.org/show_bug.cgi?id=61915

Change 120530 had a related patch set uploaded by Tobias Gritschacher:
Handle InvalidArgumentException in ClaimHtmlGenerator

https://gerrit.wikimedia.org/r/120530

Change 120530 merged by jenkins-bot:
Handle InvalidArgumentException in ClaimHtmlGenerator

https://gerrit.wikimedia.org/r/120530

Change 121678 had a related patch set uploaded by Aude:
Use DataValueMismatchException for Snak formatting [WIP]

https://gerrit.wikimedia.org/r/121678

needs to use mismatch exception consistently in more of the formatters (in data values and to-be-created EntityIdValue formatters)

also needs handling in diff formatting.

Change 121678 abandoned by Aude:
Use MismatchingDataValueTypeException for Snak formatting

https://gerrit.wikimedia.org/r/121678

see https://gerrit.wikimedia.org/r/#/c/131665/

remaining issues are that data type mismatch and undeserializable value errors are formatted inconsistently vs. how they are done in the js code, and don't have any css to indicate they are errors.