This adds the `terminfo` database to `deps/`, providing a better user
experience on systems that don't have `terminfo` on the system by
default. The database is built using BinaryBuilder but is not actually
platform-specific (it's built for `AnyPlatform`) and as such, this
fetches the artifact directly rather than adding a new JLL to stdlib,
and it requires no compilation.

A build flag, `WITH_TERMINFO`, is added here and assumed true by
default, allowing users to set `WITH_TERMINFO=0` in Make.user to avoid
bundling `terminfo` should they want to do so.

The lookup policy for `terminfo` entries is still compliant with what's
described in `terminfo(5)`; the bundled directory is taken to be the
first "compiled in" location, i.e. prepended to `@TERMINFO_DIRS@`. This
allows any user settings that exist locally, such as custom entries or
locations, to take precedence.

Fixes 55274

Co-authored-by: Mosè Giordano <giordano@users.noreply.github.com>