Implement multi-mode in Operators

[carterbox]

Moves the multi-mode and fly parameters into the operators in order to let all of the ptychography solvers share more code.

[pep8speaks]

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/ptycho/__init__.py:

Line 36:81: E501 line too long (82 > 80 characters)

Comment last updated at 2020-03-31 02:22:09 UTC