Add Django constraint to limit number of facilities for EIO and SFO

[fviduya]

Description of the Tech Debt

Operation Type SFO and EIO can have multiple facilities when manually inserted in the database. See this document for reference.

Tech Debt Triage

The purpose of our technical debt triage process is to analyze technical debt to determine risk level of the technical debt and the value in tackling that technical debt.

Risk Value Scoring:

Level	Value
High	3
Medium	2
Low	1

Technical Debt - Risk Types	Level	Value
Business Area Risk - Risk of business area visibility / damage to user experience	0	0
Developer Fault Risk - How likely will this tech debt cause a future error related to coding on top of it	0	0
System Fault Risk - Risk of system errors or application downtime	0	0
Time Scale Risk - Compound risk effect if left alone. How much more difficult to fix or dangerous will this become over time?	0	0
Time Sink Risk - How much will this tech debt slow the development process down	0	0
TOTAL SCORE:	0	0

Development Checklist:

• Checklist item
• Checklist item
• Checklist item

[fviduya]

Currently, multiple facilities can be added for EIO and SFO through manually inserting data in the database. The linked document above shows the steps. Encountered this while testing #2882.

cc: @patriciarussellCAS/@andrea-williams, please feel free to update the ticket with more dev info 🙂 thank you!