Kwplot

Added

* `util_seaborn` with helpers and workarounds

Fixed
* Issue in adjust gui

Changed
* Experimental support for PyQt6 in autompl
* Suppress headless error on BackendContext by default. The strict argument
allows the user to get old behavior.


Fixed:
* Added `kwplot.pyplot` and `kwplot.seaborn` as referenced in the documentation.

Added
* Added `corner_convention` argument to `kwplot.imshow`
* New submodule `kwplot.managers` with code ported from `geowatch.utils.util_kwplot`
* New submodule `kwplot.tables` with code ported from `geowatch.utils.util_kwplot`
* Add other functions from `geowatch.utils.util_kwplot` to existing modules
* Add `kwplot.LabelManager.force_integer_ticks()`

Changed
* `kwplot.imshow` now returns a NamedTuple with fig and ax as named alternatives to tuple indexes.
* Enabled colab `kwplot.autompl` workaround (needs a test)

Removed
* Drop 3.6 and 3.7 support

Added
* Experimental adjust-gui for normalization adjustments