https://issues.redhat.com/browse/RHOAIENG-6597

Description

When using npm run start:dev:ext, it was not possible to target an external cluster running RHOAI.

This change simply adds support for the ODH_APP env variable which can be supplied in the .env.local file. The default value remains odh-dashbaord but can be overridden to rhods-dashboard.

How Has This Been Tested?

Update .env.local to include:

OC_PROJECT=redhat-ods-applications
ODH_APP=rhods-dashboard

oc login ... to your cluster running RHOAI (use a cluster admin)
npm run start:dev:ext

Visit http://localhost:4010 to check the UI is running as expected.

Test Impact

Request review criteria:

Self checklist (all need to be checked):

• The developer has manually tested the changes and verified that the changes work
• Commits have been squashed into descriptive, self-contained units of work (e.g. 'WIP' and 'Implements feedback' style messages have been removed)
• Testing instructions have been added in the PR body (for PRs involving changes that are not immediately obvious).
• The developer has added tests or explained why testing cannot be added (unit or cypress tests for related changes)

If you have UI changes:

• Included any necessary screenshots or gifs if it was a UI change.
• Included tags to the UX team if it was a UI/UX change (find relevant UX in the SMEs section).

After the PR is posted & before it merges:

• The developer has tested their solution on a cluster by using the image produced by the PR to main