feat: separate puppeteer and puppeteer-core (#9023)

This PR moves the puppeteer source code into separate mono-repo packages:

- `puppeteer` and `puppeteer-core` are now separated into their own
packages.
- `puppeteer-core` has a new exports called `puppeteer-core/internal`
for internal usage.

Tests and various tools have been updated to accommodate the migration.

.prettierignore

@@ -8,8 +8,8 @@ lib/
 
 # Generated files
 **/*.tsbuildinfo
-puppeteer.api.json
-puppeteer*.tgz
+*.api.json
+*.tgz
 yarn.lock
 .docusaurus/
 .cache-loader
@@ -18,7 +18,9 @@ yarn.lock
 test/output-*/
 .dev_profile*
 coverage/
-src/generated
+generated/
+.eslintcache
+/.cache/
 
 # IDE Artifacts
 .vscode
@@ -34,13 +36,15 @@ src/generated
 npm-debug.log*
 yarn-debug.log*
 yarn-error.log*
+
+# Wireit
+.wireit
 ## [END] Keep in sync with .gitignore
 
 # Prettier-only ignores.
 assets/
 CHANGELOG.md
 package-lock.json
-package.json
 test/assets/
 docs/
 versioned_*/