notifications: support more complex notifications/messages

[vince-fugnitto]

Feature Description:

The framework currently supports simple notifications (strings) which are defined aligned with the behavior of VS Code and their API. The goal would be to continue supporting simple notifications from our API support but extend the framework's capabilities into allowing more complex notifications such as rendering HTML allowing additional use-cases to be supported:

Example:

• forms
• feedback

[jonah-iden]

since this is a proposal, does this still need discussion? If not i would love to implement this

[msujew]

@jonah-iden Go ahead :)