Add conversation tags

[DouglasValerio]

What is the content type?

• [ ] Bugfix
• [X] Feature
• [ ] Improvement

Why is this change necessary?

• Currently, the package does not support the addition of tags to a conversation. Recently the Zendesk team improved the native SDKs to allow tags to be set by the client side, thus allowing this improvement on the Flutter side.

How does this address the issue?

• Adds the ability for the client to set conversation tags.

[renattomachado]

+1

[renattomachado]

+1

@chyiiiiiiiiiiii @tspoke @honghai2196

Hello guys. Can you can review this PR to integrate it, please?