Windows installer for V3

[mmmarcos]

In anticipation for the upcoming Parsec v3, the following subjects should be tackled:

• [x] Base installer (already created for v3 alpha, but it is not complete: e.g. does not include WinFSP)
  • ~#1865~ <--- only relevant for v2
  • #6535
• [ ] Update strategy from v2 to v3 <--- automatic update/migration is no longer planned
  • ~Version detection compatible with v2/v3~
  • ~Parsec v2 installer that leads to the new Parsec v3 installer?~
• [ ] Update strategy within the v3 branch (need some research and discussion, maybe start RFC?), including:
  • ~#977~ <--- only relevant for v2, but contains useful information
  • #5613
• [ ] Tests robustness
  • Uninstall when the application is running
  • Atomic install/uninstall