✨ LibBytes indexOfByte

[Vectorized]

Description

Just leave it in LibBytes since this is quite byte specific, and it's intended for max perf. Wrapping it in LibString will simply add internal function call overhead.

I noticed that my old code in the older indexOf is quite unoptimized and lacks single letter variable names.
It was during a time when I could not fully visualize the stack.
The difference in style will serve as a signal to the reader on how optimized the code is.
Embrace single letter variable names.
Become one with the world stack machine.

Checklist

Ensure you completed all of the steps below before submitting your pull request:

• Ran forge fmt?
• Ran forge test?

Pull requests with an incomplete checklist will be thrown out.

[github-actions]

Gas Snapshot Comparison Report

Generated at commit : c921c57, Compared to commit : 2650456

Contract Name	Test Name	Main Gas	PR Gas	Diff
LibBytesTest	testSliceCalldata()	3110	3088	-22
	testStaticStructInCalldata()	20805	20870	65
	test__codesize()	13230	14432	1202
	testIndexOfByte()	-	5456	-
LibSortTest	testHasDuplicateGas()	297755	-	-
	testHasDuplicateOriginalGas()	451379	-	-
	testInsertionSortInts()	80477	80499	22
	testInsertionSortPsuedorandom()	63619	63574	-45
	testSearchSorted()	118950	118972	22
	testSearchSortedAddresses()	251994	251950	-44
	testSearchSortedBasicCases()	2222	2244	22
	testSearchSortedEdgeCases()	1617	1595	-22
	testSearchSortedWithEmptyArray()	687	731	44
	testSortAddressesPsuedorandom()	146920	146898	-22
	testSortAddressesPsuedorandomBrutalizeUpperBits()	198939	198982	43
	testSortAddressesReversed()	45501	45523	22
	testSortAddressesSorted()	41137	41114	-23
	testSortBasicCase()	1142	1120	-22
	testSortInts()	893932	893975	43
	testSortMostlySame()	66081	66058	-23
	testSortOriginalMostlySame()	208007	208029	22
	testSortOriginalPsuedorandom()	283683	283638	-45
	testSortOriginalReversed()	156327	156305	-22
	testSortPsuedorandom()	140190	140167	-23
	testSortSorted()	34545	34523	-22
	testSortedDifferenceDifferential()	183079	183034	-45
	testSortedUnionDifferential()	216844	216799	-45
	testUniquifySorted()	1710	1688	-22
	testUniquifySortedWithEmptyArray()	550	528	-22
	test__codesize()	25452	23514	-1938