Container Improvements in .NET Framework 3.5 Images

[mthalman]

In the February 2022 servicing release, we plan to apply new container limits improvements to the .NET Framework 4.8 version that is installed in certain .NET Framework 3.5 images:

• Container CPU and memory limits
• Allocating fewer heaps by default
• Process-isolated container support.
• Manually specifying an Environment.ProcessorCount value

These same improvements were previously applied to the .NET Framework 4.8 container images in the November 2021 servicing release. Windows Server LTSC 2022 has .NET Framework 4.8 installed by default. The .NET Framework 3.5 image based on Windows Server 2022 adds .NET Framework 3.5 on top of the base Windows Server. Starting in February, the .NET Framework 4.8 installation included with this version of the .NET Framework 3.5 image will be patched to provide these container limits improvements.

Be aware that a small set of applications have encountered issues with these changes related to memory management that required changes to work around.

Related to #866