Shaded Area Height adjustment

[dmchaplin]

Adds the ability to adjust the height of the shaded Works Area on vertical blinds. Currently, the work area is the same height as the base of the window. This is a problem with windows that are high on a tall wall. Example: a window stacked 2 or 3 levels high in a great room. It is also a problem with a work area in front of a tall window. Example: A desk in front of a floor-to-ceiling window.

Description

Added a "Shaded Area Height Adjustment" for vertical blinds. It moves the protected shaded area up (positive) or down (negative) from the base of the windows. Also increased the distance that the work area can be from the window.

Motivation and Context

• fixes:
  Variable vertical position of windows with respect to work area #367
  2 story windows? #336

How has this been tested?

I've being running my branch in my local Home Assistant since May 2nd

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Enhancement (non-breaking which updates existing code)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Other

Checklist

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.

[dmchaplin]

I didn't realize until after I submitted this PR that #369 is almost identical, but did things slightly differently.