E2E perf assessments with MSI

[gladjohn]

E2E perf scenario, where we look at:

• getting token with client_creds
• getting token with MSI
• getting token with MSI + SLC

numbers for how much time is spent in MSAL and how much time is spent in HTTP

[gladjohn]

we are still hitting global endpoint and not ests-r, global is slow, will test once we move to regional