Used constant with mapping instead of write! to display scalar value bytes

[buraksenn]

Which issue does this PR close?

• Closes Review uses of "{b:02x}" to hex-encode bytes #19569.

Rationale for this change

This was the latest usage as far as I can see so I've changed it. I think this is not on the hot path so if you want we can close the PR and issue with it.

What changes are included in this PR?

Instead of using write! format string write hex with using constant char mapping

Are these changes tested?

Runned debug display tests:

running 1 test
test scalar::tests::test_binary_display ... ok

test result: ok. 1 passed; 0 failed; 0 ignored; 0 measured; 364 filtered out; finished in 0.00s

Are there any user-facing changes?

No

[alamb]

Looks good to me -- thank you @buraksenn

I confirmed that this appears to be the last usage
https://github.com/search?q=repo%3Aapache%2Fdatafusion%20%7Bb%3A02X%7D&type=code

FYI @andygrove as you filed the original request

[andygrove]

Thanks @buraksenn!