Issue 1639 - LambdaTestTool - Sync Invoke Endpoint

[huntharo]

Issue #, if available: #1639

Relates to: #1349

Description of changes:

• Draft PR for feedback on approach
• Allows AmazonLambdaClient.InvokeAsync to work locally for testing complex projects that involve sync Invokes between a caller and Lambda
• Feedback needed:
  • Is the hard-coded function name function invoke endpoint in usage for async event testing?
    • If so, I assume I can determine the sync/async invoke type from the payload or context and only wait for sync
  • Use of Action for completion notifications - Is there a preferred alternative?
  • Thoughts on how to allow configuration of the two timeouts that were changed
    • For the immediately-returning endpoints this was not a problem, but it is a problem for sync invokes that block
    • Unfortunately it seems that Blazor does not allow changing the timeouts on a per-route basis
• The test pages were throwing exceptions due to the Response not being available
  • I made a fix but I think there may be a more comprehensive change needed for the UI?
  • My solution was acceptable for my testing: it just showed the event as still running with no response
  • When the response was received the item moved into the finished events section and a new event was processed, so there did not appear to be any harm from my approach

I have personally been using this for a week now to build and test just such a project using .NET 8.0.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.