Changes

Update DESIGN_GUIDELINES.md

Clarify guidance re. screens that are not modified and required text fields.

Update DESIGN_GUIDELINES.md

Update DESIGN_GUIDELINES.md

Update DESIGN_GUIDELINES.md

Clarify the information sources that are admissable for a prototype to be considered unambiguous.

Fix AddSchoolUseCase: AddSchoolUseCase incorrectly set approval required after on the sys admin role invite in the distant future.

Update DESIGN_GUIDELINES.md

Update DESIGN_GUIDELINES.md

disable pending request for self enable case