WiFiManager updates

[justmobilize]

This:

1. renames ESPSPI_WiFiManager to WiFiManager and updates the signature to not take in secrets
2. create a new ESPSPI_WiFiManager that subclasses WiFiManager and coverts the secrets to params
3. updates all examples to not use secrets
4. Shows warnings when methods are passed secrets

[dhalbert]

This looks great! I made some doc changes (phrasing and capitalization), and some minor code simplifications.

If this looks good to you, you should be able to use "Add suggestion to batch" on each of the changes, and then commit all the changes at once in a single commit, both via the GitHub web user interface.

After that, before merging, I will test one or more of the test programs on an AirLift board.

[justmobilize]

@dhalbert accepted them all and fixed another typo

[dhalbert]

@justmobilize

I tested esp32spi_simpletest.py and esp32spi_locatime.py. The first worked, the second had a keyword arg error. Turns out there were a few new keyword status_light= args in the examples, but they were meant to be status_pixel. I pushed a commit that changed all mentions status_light to status_pixel, to be more consistent, to avoid status_pixel=status_light args. Is this OK by you? If that's fine, I'll approve and merge.

EDIT: I also tested the old version of esp32spi_localtime.py, which printed the expected warning, and then continued on and fetched the time.

[justmobilize]

@dhalbert thanks for catching that. Please merge away! Will start updating other libs once this is released