Just skip validation if it is a GET form and the current input is an
empty string. Callers will need to check that it is not the empty string
though.
Also make sure HTMLForm::mMethod is always lowercase.
Change-Id: I605f32048fe97eebd7e04b6ffd799759aeb7f31e
HTMLTitleTextField will automatically validate title input, can
optionally ensure the title is in a specific namespace, is creatable, or
already exists.
The field currently doesn't support GET requests since validation on
empty strings fails.
Bug: T104420
Change-Id: I45718462570d0a523a148c3830b1116b634df050
