Build projects with net8

[ilijagrbic]

Motivation

This PR introduces changes that are needed for multiple reasons.
Firstly, we will migrate away from netstandard2.0->net8.0 during the effort to support Mariner for SF. So, we are making similar migration here.

Other changes

• Build all of the projects in this repo with net8.0 (instead of netstandard2.0)
• Clean up property files
• Other minor cleanup such as removing unnecessary properties, moving common properties to common files etc.

[olegsych]

Thanks @ilijagrbic. I really like the direction of this PR. But let's keep it focused on netstandard2.0 -> net8.0 only and exclude the Linux changes for now. I'm concerned that even without Linux, we have a lot of significant changes, so let's slow down and think this through.

One particular reason for excluding Linux changes from this PR is that looking at the amount of complexity and confusion we're adding by repurposing the runtime-neutral TargetFramework net8.0 for a specific OS made me go back and think of other options. I think a simpler solution is to check if the process is running on Linux at runtime using OperatingSystem.IsLinux() or RuntimeInformation.IsOSPlatform(). That way we can continue building a single net8.0 binary.