Improve and streamline MSYS2 installation (#7232)

Improve and streamline MSYS2 installation (#7232)

* Make MSYS force install

* Cleanup msys script

* Update to gcc 8.3 for arm and avr

And cleanup install scripts for both

* Fix path and scripts

* Fix links

* No confirmation for msys

* Tweak arm function since file structure changed

* Fix spacing and wording

Co-Authored-By: fauxpark <fauxpark@gmail.com>
* Only use MSYS2's make binary

Co-Authored-By: fauxpark <fauxpark@gmail.com>
* Some wordsmithing

Co-Authored-By: Mikkel Jeppesen <2756925+Duckle29@users.noreply.github.com>
* Add "disable download timeout" for download issues in MSYS

Co-Authored-By: Mikkel Jeppesen <2756925+Duckle29@users.noreply.github.com>
* Clean up URL for arm gcc download

Co-Authored-By: Joel Challis <git@zvecr.com>
* add pip

Co-Authored-By: fauxpark <fauxpark@gmail.com>