Open message actions bottom sheet on single-tap?

It makes sense that e.g. in room list, single-tap opens the room and long-tap opens the room's bottom sheet.
But for messages, single-tap is unactionable (there's only a visual ripple) and long-tap opens the message's bottom sheet.
I suggest that we make bottom sheet on single-tap and long-tap is either no-op or implement the "message multi-selection" action where you can select multiple messages (#3169) and do an action (forward/delete/etc.) on them in a a batch.

@mxandreas @americanrefugee PTAL

Start with the message interaction code in the relevant Element client; the issue names the room list, message bottom sheet, and issue #3169 as the key entry points. Confirm the intended choice with the maintainers, then verify that a single tap opens the message bottom sheet and that long-tap either does nothing or supports the multi-selection behavior described in #3169.

Written by the indexing model from the issue text.