Mangle exported symbols (#182935)

* Mangle exported functions

For #180461

This prototype tries to mangle exported functions, saving a further 440kb from the bundle size

* Fix missing call

* Also try mangling top level exported consts too

* Fixing errors

* Don't run on build files

* Skip a few more manglings and revert change to namespace

* Skip a few more monaco files

* Also mangle consts that shadow types

This increases savings up to 3325

* Also mangle exported classes

* Skip mangling more localization functions for now

* Opt out pfs

* Update build script

* Run find locations task in parallel

This should speed up compile

* Cleanup before close

* Limit workers to avoid hitting memory limit

* Limit pool size

* Skip one more mangling

* Exclude entrypoints from mangling

* Try to fix web build and clean up code

* Exempt a few more projects

* Exempt another file

* Also exempt html

* Skip mangling ext entrypoints

* Use prefix that can't be confused with rpc calls

* Fix max call stack error

* Switch prefixes

* Don't mangle ambient declarations

* Use correct way of checking modifier flags

* Workaround getCombinedModifierFlags not doing what I'd expect

Maybe needs the checker to be enabled too? Just check parent chain instead for now

* Clean up code and add logic showing how enum mangling could work

* Remove a few more skipMangles

Use entrypoints instead

* Fix entrypoint name