Backport WikiMap/JobQueueGroup logic to handle hyphenated DB names

Although the documentation in DefaultSettings.php states that such
cases should be avoided, some common cases and code paths can be
made to work easily enough.

Partially cherry-picked from dcd0a3d53, 51945dbca3594, and 5196ac32c6.

Bug: T204423
Change-Id: Ia3c5855b18b98d9fc5bc02fe68358cfa52ccbce1