Fix module compatibility, SVG className crash, deprecated API and also add TypeScript types

[Tejakshaya]

• fixed getComputedStyle polyfill crashing in module contexts (React, Vue, ES modules) where this is undefined
• replaced deprecated getPropertyCSSValue() with getPropertyValue() (removed from Chrome since v41)
• fixed show() and resetAnimation() crashing on SVG elements by replacing className manipulation with classList API
• added TypeScript type definitions (dist/wow.d.ts) and types field in package.json

Changes:

getComputedStyle polyfill ( fixes issues #352 and #372 ) -> the polyfill set this.getPropertyValue = ... and returned this, but in strict mode / module scope, this is undefined which causes Cannot set properties of undefined (setting 'getPropertyValue'). Now creates and returns a plain object instead

Deprecated getPropertyCSSValue ( fixes #358 ) -> vendorCSS() used getPropertyCSSValue() which was removed from Chrome in v41 (2015) and was replaced with getPropertyValue() and also simplified animationName() by removing the completley unnecessary try/catch and .cssText access

SVG className (fixes #349) -> show() and resetAnimation() used element.className directly which returns an SVGAnimatedString on SVG elements and replaced with classList.add() / classList.remove() which work on both HTML and SVG elements, also supersedes #354 ( stale since 2021, only fixed resetAnimation )

TypeScript types (fixes #351) -> added dist/wow.d.ts with type definitions for the WOW class and WOWOptions interface and now supports both default and named exports

Closes #349
Closes #351
Closes #352
Closes #358
Closes #372

Prexisting issue: The 'requestAnimationFrame' in window check on line 337 crashes when window is undefined but that's in the original code and out of scope

[veraLX]

Hello，我是林昕，我已收到来信~