feat: Fully unblock Excel's main thread when starting many prompts

[kaspermarstal]

No description provided.

[sentry]

Suspect Issues

This pull request was deployed and Sentry observed the following issues:

• ‼️ System.Collections.Generic.KeyNotFoundException: Unable to find a resilience pipeline associated with the key 'RateLimiter'. Please ensure that either the resilience pipeline or the builder is registered. Models\Client.cs in async Task<Prompt> Client.G... View Issue
• ‼️ Cellm.AddIn.Exceptions.CellmException: Empty cells A22:B23 AddIn\ArgumentParser.cs in string ArgumentParse... View Issue

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