block: check box to file a meta:SRG global lock request

[NovemLinguae]

I propose adding a check box to the block module that, when checked, files a meta:SRG (Steward Requests/Global) request to global lock the account. This comes in handy when doing username blocks of LTAs and really malicious usernames.

• add check box and description to block module front end
• use ForeignAPI to see if user is already globally locked. if so, gray out check box or something
• use ForeignAPI to write the request to meta:SRG