🏗 Rewrite dep-check with esbuild and babel

[rsimha]

This is another in a series of PRs that modernize our development tasks.

PR highlights:

• Rewrite dep-check with esbuild and babel
• Rewrite getSrcs(), which was only writing one file (and rename it to getEntryPointModule())
• Rewrite getGraph() to use esbuild and babel (and rename it to getModuleGraph())
• Clean up flattenGraph()
• Eliminate the use of browserify, babelify, gulp.dest, and vinyl-source-stream
• Delete vinyl-source-stream from package.json (others need more work)

Screenshots:

Reference: https://esbuild.github.io/api/#metafile

Partial fix for #32585

[samouri]

Doesn't esbuild have an optional "metafile" with the entire dep tree?
See: https://esbuild.github.io/api/#metafile

[rsimha]

Doesn't esbuild have an optional "metafile" with the entire dep tree?
See: esbuild.github.io/api/#metafile

Nice! Done in latest commit.