Add credscan to Azure pipelines

[MIchaelMainer]

Is your feature request related to a problem? Please describe.

All repos should run credscan task to make sure we are not checking in credentials.
https://github.com/microsoftgraph/microsoft-graph-explorer-v4/blob/dev/azure-pipelines.yml

Describe the solution you'd like

- task: securedevelopmentteam.vss-secure-development-tools.build-task-credscan.CredScan@2
  displayName: 'Run CredScan'
  inputs:
    debugMode: false

We will likely have to add a suppression file since we have samples that have password in them.

Additional context
This addresses OXO4007424.

AB#7510