Prepare release for 1.8.4

[ConnorMcMahon]

• Update to version 1.8.4
• Use DurableTask.AzureStorage to 1.6.5
• Update samples to use new version.

[ConnorMcMahon]

There are 3 open issues on the milestone that aren't fix-ready or documentation tagged.

#771 - I'm hesitant to move forward on this issue until a non-prerelease of Microsoft.NET.Sdk.Functions that unblock 2.3.0 usage moves forward.

#951 - Not sure how much work needs to be done on the extension side to light this up. Will investigate.

#934 - Not sure if this is something we can address until we support BYO serialization, which is likely a 2.0 only feature. The customer has a workaround, so I don't necessarily want to hold on the release for this.

[cgillum]

These changes look good to me. What's the plan for #771? Is this something Fabio's team is working on? Also, I'm fine punting #934 if it's not straightforward.

[ConnorMcMahon]

I pinged Fabio in one of the core open issues in the corresponding repo, so I will know soon regarding that issue.

[amdeel]

Is the intention to update to the newest version, 1.6.5?

[ConnorMcMahon]

Good call!

[amdeel]

The #934 fix would probably include custom serialization settings in DurableTask.Core, the changes that I am currently working on. I can prioritize this work if it would help.