Move ViewTransitions helpers to ReactFiberCommitViewTransitions

[sebmarkbage]

This doesn't change anything. It just moves some functions.

This moves the view transitions helper functions into its own file. This is similar to how I already moved ReactFiberCommitEffects and ReactFiberCommitHostEffects out of ReactFiberCommitWork.

This makes it a bit easier to navigate and get an overview of ReactFiberCommitWork but another motivation is also so that I can refer to these helpers from ReactFiberApplyGesture.

[react-sizebot]

Comparing: 9b042f9...acd25c1

Critical size changes

Includes critical production bundles, as well as any change greater than 2%:

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
oss-stable/react-dom/cjs/react-dom.production.js	=	6.68 kB	6.68 kB	+0.11%	1.83 kB	1.83 kB
oss-stable/react-dom/cjs/react-dom-client.production.js	=	515.71 kB	515.71 kB	=	92.09 kB	92.09 kB
oss-experimental/react-dom/cjs/react-dom.production.js	=	6.69 kB	6.69 kB	+0.11%	1.83 kB	1.83 kB
oss-experimental/react-dom/cjs/react-dom-client.production.js	=	565.64 kB	565.63 kB	+0.02%	100.84 kB	100.86 kB
facebook-www/ReactDOM-prod.classic.js	=	636.70 kB	636.69 kB	=	112.08 kB	112.07 kB
facebook-www/ReactDOM-prod.modern.js	=	627.02 kB	627.01 kB	=	110.50 kB	110.48 kB

Significant size changes

Includes any change greater than 0.2%:

(No significant changes)

Generated by 🚫 dangerJS against 2363f87