add view --interpolation option

[scottstanie]

Description of proposed changes

Adds the ability to specify a matplotlib option on the command line for view.py, e.g. mintpy view --interpolation nearest.
After implementing this, I saw it was already on the wiki To Do list.

The other changes were small typos I had seen pop up on my spell checker. I can split them off if you don't want them in this PR.

Reminders

• Pass Pre-commit check (green)
• Pass Codacy code review (green)
• Pass Circle CI test (green)
• Make sure that your code follows our style. Use the other functions/files as a basis.
• If adding new functionality, add a detailed description to the documentation and/or an example.

[yunjunz]

Thank you @scottstanie. Looks all good to me. Great to see you checked the to-do list as well.