Speed up snapshotting of many new dom nodes (#903)

* Speed up snapshotting of many new dom nodes

By avoiding reflow we shave about 15-25% off our snapshotting time

* Improve newlyAddedElement docs

* Optimize needMaskingText by using el.closest and less recursion

* Serve all rrweb dist files

* Split serializeNode into smaller functions

Makes it easier to profile

* Slow down cpu enhance tracing on fast machines

* Increase timeout

* Perf: only loop through ancestors when they have something to compare to

* Perf: `hasNode` is cheaper than `getMeta`

* Perf: If parents where already checked, no need to do it again

* Perf: reverse for loops are faster

Because they only do the .lenght check once. In this case I don't think we'll see much performance gains if any

* Clean up code

* Perf: check ancestors once with isBlocked

* guessing this might fixes canvas test

* Update packages/rrweb/src/record/observers/canvas/webgl.ts

Co-authored-by: yz-yu <yanzhen@smartx.com>

* Fix #904 (#906)

Properly remove crossorigin attribute

* Bump minimist from 1.2.5 to 1.2.6 (#902)

Bumps [minimist](https://github.com/substack/minimist) from 1.2.5 to 1.2.6.
- [Release notes](https://github.com/substack/minimist/releases)
- [Commits](https://github.com/substack/minimist/compare/1.2.5...1.2.6)

---
updated-dependencies:
- dependency-name: minimist
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Co-authored-by: yz-yu <yanzhen@smartx.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

packages/rrweb-snapshot/src/utils.ts

@@ -13,7 +13,7 @@ export function isElement(n: Node): n is Element {
 
 export function isShadowRoot(n: Node): n is ShadowRoot {
   const host: Element | null = (n as ShadowRoot)?.host;
-  return Boolean(host && host.shadowRoot && host.shadowRoot === n);
+  return Boolean(host?.shadowRoot === n);
 }
 
 export class Mirror implements IMirror<Node> {