Consider Adding Codec to work with Hex Strings

(you don't have to strictly follow this form)

**Use case**

Better compression for hex strings, such as "813031B8BBC3B329"

**Describe the solution you'd like**

Hex Strings are used in many applications to represent short binary data in printable form
While ClickHouse has hex() and unhex() functions it is intrusive to the application

**Describe alternatives you've considered**

Some different data type which stores data as binary but displays it in hex would be alternative but I assume it is much more labor intensive while unhex() codec might be easier.

Of course codec would need to be able to reject non-hex data input as invalid in this case.

**Additional context**

Simply storing hex strings as strings compared to converting them to binary results in 10-15% performance overhead, which is not significant. However column also takes some 80% more on disk using LZ4 compression which to my surprise is unable to compress such data well.