[iOS] Remove <Webkit/Webkit.h> import in RCTConvert.h

[Saadnajmi]

Summary:

This PR is in response to #39758 (comment) .

RCTConvert.h currently takes an import of <Webkit/Webkit.h> for... one enum: WKDataDetectorTypes. This has a few problems:

1. RCTConvert is JS engine agnostic, it shouldn't be depending on Webkit
2. As far as I can tell, this code is dead, we also define (and use) the UIKit equivalent UIDataDetectorTypes.

Let's just combine the two, update some JS typing, and get rid of the Webkit header import.

Changelog:

[IOS] [CHANGED] - Remove <Webkit/Webkit.h> import in RCTConvert.h

Test Plan:

CI should pass

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	16,901,404	-21
android	hermes	armeabi-v7a	n/a	--
android	hermes	x86	n/a	--
android	hermes	x86_64	n/a	--
android	jsc	arm64-v8a	20,380,171	-4,094
android	jsc	armeabi-v7a	n/a	--
android	jsc	x86	n/a	--
android	jsc	x86_64	n/a	--

Base commit: c4110d0
Branch: main

[github-actions]

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@NickGerleman has imported this pull request. If you are a Meta employee, you can view this diff on Phabricator.

[facebook-github-bot]

@NickGerleman merged this pull request in 452bf0f.