BED-5504: moves useIntialEnvironment to shared-ui

[benwaples]

Description

This PR:

• Moved useInitialEnvironment to shared-ui so we can use it in BHE.
• Changes useEnvironment (new hook from deep linking) return value to include environmentAggregation and environment.
• Cleans up globally supported search param from router as its no longer needed

Motivation and Context

This PR addresses: BED-5504

Supports changes in BHE

How Has This Been Tested?

Regression tested

Screenshots (optional):

Types of changes

• Chore (a change that does not modify the application functionality)

Checklist:

• I have met the contributing prerequisites
  • Assigned myself to this PR
  • Added the appropriate labels
  • Associated an issue: Issues and Pull Requests README #672
  • Read the Contributing guide: https://github.com/SpecterOps/BloodHound/wiki/Contributing
• I have ensured that related documentation is up-to-date
  • Open API docs
  • Code comments (GoDocs / JSDocs)
• I have followed proper test practices
  • Added/updated tests to cover my changes
  • All new and existing tests passed

[benwaples]

I ended up including these properties in the return value from this hook out of convience. It allows us to get the environment as const { environment } = useSelectedEnvironment() and create a state switch with redux really easily