keysym: fast path for case sensitive xkb_keysym_from_name

keysym: fast path for case sensitive xkb_keysym_from_name

xkb_keysym_from_name() is called a lot in Compose file parsing. The
lower case handling slows things down a lot (particularly given we can't
use the optimized strcasecmp() due to locale issues). So add separate
handling for the non-case-sensitive case which is used by Compose.

To do this we need to add another version of the ks_tables table. This
adds ~20kb to the shared library binary. We can probably do something
better here but I think it's fine.

Signed-off-by: Ran Benita <ran@unusedvar.com>