3rdparty: Add msvc2019 compilation support
I altered the 3rdparty libraries to support msvc2019 compilation
I have already tested the whole compilation and building process using a batch file running from a msvc x64 command prompt from the b folder as suggested in the README file resides in the 3rdparty folder, in addition there would be another MR supporting the msvc2019 build for the application
- I confirmed this builds.
- I confirmed Krita ran and the relevant functions work.
- I tested the relevant unit tests and can confirm they are not broken. (If not possible, don't hesitate to ask for help!)
- I made sure my commits build individually and have good descriptions as per KDE guidelines.
- I made sure my code conforms to the standards set in the HACKING file.
- I can confirm the code is licensed and attributed appropriately, and that unattributed code is mine, as per KDE Licensing Policy.