add tag to TaskScheduledEvent

[YunchuWang]

This pull request introduces a new property, Tags, to the TaskScheduledEvent class in src/DurableTask.Core/History/TaskScheduledEvent.cs. This property is a dictionary designed to store key-value pairs of strings, providing a flexible way to include additional metadata.

Related prs:
https://github.com/microsoft/durabletask-protobuf/pull/43/files
microsoft/durabletask-dotnet#426
https://msazure.visualstudio.com/One/_git/AAPT-DTMB/pullrequest/12388270

Key Change:

• Added a new Tags property to the TaskScheduledEvent class. This property is an IDictionary<string, string> with a default initialization to an empty dictionary, allowing for the storage of string-based key-value metadata.

[cgillum]

It's a bit odd that we create this history event but don't expose any way for DTFx users to set it. I'm okay with this if we want to expose it via other libraries, but let's wait to merge it until we have a PR (in this repo or another repo) that actually uses the property in some end-to-end way.

[YunchuWang]

hi @cgillum , i made more changes, can you take a look when have chance? thanks

[cgillum]

I'm worried that these overloads might be accidental breaking changes. Maybe we should revert those changes and only update the history events, which is what we did in the first version of your PR.

[cgillum]

I haven't not read the new tests closely yet, but here is some feedback for now.

[YunchuWang]

@cgillum hi Chris, comments addressed, all tests are passing, can you take another look? thanks