Use platformdirs over appdirs

[iLLiCiTiT]

Please describe the feature you have in mind and explain what the current shortcomings are?

Python module appdirs is used to get default local storage paths, but the module is not maintained for more than 3 years and officially deprecated for a year.

How would you imagine the implementation of the feature?

The module repository itself refers to platformdirs as more up-to-date and maintained repository, which is fork of original appdirs.

The change has to be carefully applied and validated to be sure we can use platformdirs in AYON launcher and appdirs in ayon-core for some time. If it won't be possible it would meant minor release of both repositories without compatibility to older versions.

Sooner this happens, the smoother the transition will be.