rrdom (#613)

* create rrdom package

* test(rrdom): add unit tests for polyfill.ts

* fix(rrweb snapshot): type check errors

Errors are caused by the declaration similarity of @types/mocha and @types/jest if we install both of them in the whole project.

* Set tagNames to upper case by default

This mirrors the `Element.tagName` implementation:

```
For DOM trees which represent HTML documents, the returned tag name is always in the canonical upper-case form. For example, tagName called on a <div> element returns "DIV".
```
https://developer.mozilla.org/en-US/docs/Web/API/Element/tagName

* Add workspace file

* VSCode settings for rrdom tests

* Add basic test for RRDocument

* Only setup jest tests for rrdom

* mock Node type and Event type for nodejs environment

* test(rrdom): add snapshot for document.test.ts

* fix issue of nwsapi import and add unit tests for rrdom

* fix: querySelectorAll returns nothing when querying elements with ids and classNames

* fix: error of unit test for Event polyfill

Since Event class is built in nodejs after v15.0.0

* add a dummy implementation of canvas

* add style element support

* add unit test for style element

Co-authored-by: Justin Halsall <Juice10@users.noreply.github.com>

packages/rrdom/tsconfig.json

@@ -0,0 +1,19 @@
+{
+  "compilerOptions": {
+    "target": "es5",
+    "module": "commonjs",
+    "noImplicitAny": true,
+    "strictNullChecks": true,
+    "removeComments": true,
+    "preserveConstEnums": true,
+    "sourceMap": true,
+    "rootDir": "src",
+    "outDir": "build",
+    "lib": ["es6", "dom"],
+    "skipLibCheck": true,
+    "declaration": true
+  },
+  "compileOnSave": true,
+  "exclude": ["test"],
+  "include": ["src", "test.d.ts"]
+}