According to the discussions at Bug T254649 and Bug T254646
rename the lists to generic "allowed titles" and "disallowed titles"
lists.
The previous change was abandoned, probably because it tried
to say "blocklist", which can be confused for user blocking.
I see there is intention to merge this extension's functionality
into AbuseFilter, but until it happens, it would be nice
to rephrase the user-visible messages at least.
Also make the spelling of "username" and "case-insensitive" consistent
with core MediaWiki, and a few other copy editing fixes,
and fix some tests with these words.
Bug: T254650
Change-Id: I05ccc585325eb1610dd6b257a0b96ab43b0c8c8f