NEW: Solve the lamino-alignment problem

Purpose

Provide a function for solving the lamino-alignment problem with ADMM.

Approach

Solve the laminography + alignment problem using the Laminography operators, Lanczos Interpolation operator, and Flow solver which wraps OpenCV's Farneback's method.

Also includes some changes to the ThreadPool and scatter/gather CUDA kernels which should be merged separately.

Pre-Merge Checklists

Submitter

[ ] Write a helpfully descriptive pull request title.
[ ] Organize changes into logically grouped commits with descriptive commit messages.
[ ] Document all new functions.
[ ] Write tests for new functions or explain why they are not needed.
[ ] Build the documentation successfully
[ ] Use yapf to format python code.

Reviewer

[ ] Actually read all of the code.
[ ] Run the new code yourself.
[ ] Write a summary of the changes as you understand them.
[ ] Thank the submitter.

Hello @carterbox! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

In the file src/tike/admm/pal.py:

Line 137:21: E131 continuation line unaligned for hanging indent Line 141:21: E131 continuation line unaligned for hanging indent

In the file src/tike/admm/subproblem/__init__.py:

Line 35:1: E402 module level import not at top of file Line 36:1: E402 module level import not at top of file Line 37:1: E402 module level import not at top of file