Increase request timeout to match default retry attempts.

[peombwa]

This PR proposes:

• Increases the default HTTP client timeout to 300 seconds. This works out to 100 seconds per retry attempt. Our default max retry-attempt is fixed at 3. Closes Increase HTTP Request Timeout #1013.
• Adds -ClientTimeout parameter to Connect-MgGraph. This parameter allows customers to configure an HTTP client timeout when throttled requests respond with a retry-after header > the client's default of 300 seconds.
• Fixes bug in Invoke-MgGraphRequest that made it not throw exceptions on error in certain conditions. Closes Invoke-MgGraphRequest Should Always Throw on Error #1014.

Tests

1. Using default timeout of 300 seconds.
   

2. Using a timeout of 10 seconds.
   

Related to timeouts being experienced by customers when running https://docs.microsoft.com/en-us/troubleshoot/azure/active-directory/enable-support-tls-environment?tabs=powershell#overview-of-new-telemetry-in-the-sign-in-logs.