The protocol enables robust key reporting for the applications, so
they could bind more keys and the user won't have collisions with
the normal control keys.

Links: https://sw.kovidgoyal.net/kitty/keyboard-protocol
Fixes #6378.

Remove the DCS sync updates escape sequence since it's no longer
supported.

Fixes: 47d500770a (Bump VTE to 0.12.0)

The wiki contains a list of links to ANSI references:
https://github.com/alacritty/alacritty/wiki/ANSI-References

Co-authored-by: Christian Duerr <contact@christianduerr.com>

This switches Alacritty's default configuration format from yaml to
toml. While yaml is still supported, it is done by converting it to toml
and should be removed entirely in the future.

All existing features were persisted based on my testing. Behavior
should not change much, though `--option` might have slightly different
behavior since the entire line is not interpreted as one line of toml.

A new `alacritty migrate` subcommand has been added which allows
automatic migration from yaml to toml. This also could be used as a
facility to automatically fix configuration file changes in the future.

Closes #6592.

This commit adds support for hyperlink escape sequence
`OSC 8 ; params ; URI ST`. The configuration option responsible for
those is `hints.enabled.hyperlinks`.

Fixes #922.