Wiregrid Actuator Agent: Add 'position' data in session.data

[d-hoshino2626]

Description

I added 'position' data, which means the wiregrid is in the view of the telescope ('inside') or out of the view ('outside'), in session.data.

Motivation and Context

This change enables to monitor the location of the wiregrid easily.

How Has This Been Tested?

no test

Types of changes

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

Checklist:

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

[BrianJKoopman]

This looks good to me, thanks for moving this over from runlib. Any plans to test before we squash and merge?