Improved scan performance

[kirillgarbar]

Proposed Changes

Exclude scan is rewritten so it uses less kernel calls and no cycles outside of kernels.
Other versions of scan left unchanged because they are rarely used and may be reworked later so I can focus on further performance analysis.
We also had two Common.PrefixSum modules and it was confusing if we are using api module or internal one.
New scan code looks so unusual because we can't directly use recursion and compile time kernel translation at the same time.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• Build and tests pass locally
• I have added tests that prove my fix is effective or that my feature works (if appropriate)
• I have added necessary documentation (if appropriate)

[gsvgit]

Can we use obsolete attribute here?