Move Adaptive Card to separate crate

[My-]

I believe it would make sense to have Adaptive Card as a separate crate as it could be reused in other projects too.

[aknarts]

I want to start a discussion on this.

I personally do not think this is a good idea as the Webex implementation of AC is kind of specific and we do not support the full feature set that AC provides from upstream, only what Webex does.

[grnmeira]

@My- would you have any examples of projects that would use this separately from the API crate? What would you have in mind?

[Erk-]

@My- would you have any examples of projects that would use this separately from the API crate? What would you have in mind?

I went looking for a Adaptive Card crate not for webex, but for MS Teams since it also uses that.

Though it probably makes sense to keep it internal if it is too specific to webex.

[aknarts]

Adding to that I think we only have features in the module that are actually supported by Webex.