Share templates

### Description

Related to #141 but this may have multiple separate stories to split out

**As a:** user

**I want to:** share templates I have created with other teams.

**So that:** Others can build on my work

Considerations:
- Can any user share a template or is the owner only?
- There should be 2 types of sharing, public and private
- In public the user is given a url for their template that they can publish, send so any other user on the platform can open and use the template, to allow for creating tutorial blog posts etc.
- In private the user explicitly sends the template to another named team, the owner is then invited to accept or reject the template.
- Public templates would only be scoped to system boundary, so FlowForge.cloud template urls wouldn't be usable on a local instance.