Add overridable hooks for bridgeless creation

[Kudo]

Summary:

add overridable hooks for RCTHost and RCTSurfaceHostingProxyRootView. this are required for expo's pluggable system to serve expo-dev-client and expo-updates integration.

this pr introduces new createSurfaceViewWithReactHost:moduleName:initProps: and changes createReactHost for returning an instance rather than mutating member variables.

this pr is based on 0.74-stable only since on main there's ec928d7 which is good enough for the use case.

Changelog:

[IOS] [ADDED] - Add overridable hooks for bridgeless creation in RCTAppDelegate

Test Plan:

ci passed

[analysis-bot]

Platform	Engine	Arch	Size (bytes)	Diff
android	hermes	arm64-v8a	17,816,397	-237,088
android	hermes	armeabi-v7a	n/a	--
android	hermes	x86	n/a	--
android	hermes	x86_64	n/a	--
android	jsc	arm64-v8a	21,174,775	-233,154
android	jsc	armeabi-v7a	n/a	--
android	jsc	x86	n/a	--
android	jsc	x86_64	n/a	--

Base commit: e2157f0
Branch: main

[huntie]

Thanks @Kudo. We were able to merge all of #43325 instead :).