refactor: Extract clean_query_lowercase().
refactor: Extract clean_query_lowercase().

This makes it a bit easier to find common patterns,
plus it sets us up to pull the calls even further
up the stack.

The first rule of dealing with user data is sanitize
at the edges, not deep down in some function that
has many callers.  Putting this code so deep down
in the stack means it's more likely to be called in
a loop.

synicalsyntax/zulip,showell/zulip,andersk/zulip,brainwane/zulip,shubhamdhama/zulip,brainwane/zulip,eeshangarg/zulip,punchagan/zulip,shubhamdhama/zulip,eeshangarg/zulip,shubhamdhama/zulip,rht/zulip,hackerkid/zulip,timabbott/zulip,eeshangarg/zulip,zulip/zulip,showell/zulip,showell/zulip,shubhamdhama/zulip,kou/zulip,punchagan/zulip,andersk/zulip,andersk/zulip,brainwane/zulip,punchagan/zulip,showell/zulip,rht/zulip,brainwane/zulip,punchagan/zulip,zulip/zulip,shubhamdhama/zulip,synicalsyntax/zulip,hackerkid/zulip,kou/zulip,timabbott/zulip,synicalsyntax/zulip,eeshangarg/zulip,rht/zulip,brainwane/zulip,rht/zulip,shubhamdhama/zulip,kou/zulip,timabbott/zulip,andersk/zulip,synicalsyntax/zulip,shubhamdhama/zulip,andersk/zulip,zulip/zulip,timabbott/zulip,zulip/zulip,eeshangarg/zulip,punchagan/zulip,kou/zulip,punchagan/zulip,punchagan/zulip,rht/zulip,synicalsyntax/zulip,hackerkid/zulip,kou/zulip,brainwane/zulip,timabbott/zulip,eeshangarg/zulip,rht/zulip,zulip/zulip,showell/zulip,zulip/zulip,zulip/zulip,hackerkid/zulip,synicalsyntax/zulip,brainwane/zulip,andersk/zulip,timabbott/zulip,showell/zulip,hackerkid/zulip,kou/zulip,hackerkid/zulip,rht/zulip,eeshangarg/zulip,timabbott/zulip,showell/zulip,hackerkid/zulip,synicalsyntax/zulip,andersk/zulip,kou/zulip