runtime(odin): support underscore-separated numeric literals

runtime(odin): support underscore-separated numeric literals

Add support for underscore-separated numeric literals in Odin syntax
highlighting. This allows proper highlighting of numbers like 1_000_000,
0xFF_AA_BB, and 0b1010_1111 as specified in the Odin language.

>  Numerical literals are written similar to most other programming
>  languages. A useful feature in Odin is that underscores are allowed
>  for better readability: 1_000_000_000 (one billion).
>  https://odin-lang.org/docs/overview/#numbers

closes: #18852

Signed-off-by: Maxim Kim <habamax@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>