fix(wayland)!: hardcode client-side decorations; hardcode scale=1.0

[jokeyrhyme]

• this PR addresses some panics in https://github.com/wez/wezterm/pull/4777#issuecomment-1913452992 by hardcoding client-side decorations (instead of trying to negotiate for server-side decorations) and hardcoding scale=1.0 (instead of using detected monitor/surface values)
• this does mean user preferences are not honoured, however, the terminal is in a mostly usable state

future PRs:

• restore/improve visual experience of CSD title-bar per https://github.com/wez/wezterm/pull/4777#issuecomment-1915849032
• use detected output/surface scale instead of hardcoding to 1.0
• other ideas from: https://github.com/wez/wezterm/pull/4777#issuecomment-1913394104
• hidden/absent CSD when SSD is offered by compositor
• update to smithay-client-toolkit 0.18 (let's do this after we've got everything back to normal again)

[wez]

FWIW, I had this cherry-picked and rebased on top of my rebase of #4777 (which is now in main) and it would exit immediately after launch, so there is something not quite right here. My test is simple:

• Run wayfire in a window of its own
• WAYLAND_DISPLAY=wayland-1 ./target/debug/wezterm

that works in main but exits with this PR.

My display is hidpi, in case that is relevant

[jokeyrhyme]

Huh, my display is scale=1.25 here, let me see...

[jokeyrhyme]

Bah, I pressed "Resolve conflicts" in GitHub and it did a git merge

And there's still conflicts :S