Fixes #819

Port c875f19673 to glitch-soc

Partially port 90b64c0069

Port 3cecf3e5b9 to glitch-soc

Port dd00cd19d2 to glitch-soc

Port 2b51b4094c to glitch-soc

Port ccbdf689e8 to glitch-soc

Port bb5558de62 to glitch-soc

Port f59b840549 to glitch-soc

Port 9c38c5daa3 to glitch-soc

Port 795f0107d2 to glitch-soc

Port e961a763a2 to glitch-soc

Port 5ee0b51ac8 to glitch-soc

e.g., typing “blob_cat_p” used to search for “blob” and “cat”, but not
“blob_cat_p”, which means “blob_cat_patpat” is very unlikely to show up,
although it is likely what the user wanted to type in the first place.

Port 6e1a4f85ad to glitch-soc

Port 7861c5f108 to glitch-soc

Port bebe8ec887 to glitch-soc

Port c73864c137 to glitch-soc

Port 3a157210c8 to glitch-soc

Port bf58461d36 to glitch-soc

Port 25f9ead041 to glitch-soc

Port 029943d59b to glitch-soc

Port 065b39e7a4 to glitch-soc

Port 301cbcc980 to glitch-soc

Port 65b3804a6c to glitch-soc

Port d35801aaa2 to glitch-soc

Port f8c1b32541 to glitch-soc

Port efd09e2ebb to glitch-soc

Port b972478812 to glitch-soc

Indeed, when the “Always enable the Content Warning field” setting is enabled,
sending a content-less toot with a CW would move the CW to the toot's content
and leave the toot not marked as sensitive.

Fixes #780

Fixes #778