[FR] Support backlinks v0.1

### Description

Every time there is a link in `PageA` to `PageB`, automatically create a backlink in `PageB` to `PageA`

The link should be at the block level.
The page title name should automatically get updated in the backlink.
The link should have a type property, representing the relationship type or the weight of the link between two connected objects. This will not be used in v0.1.

This feature should be implemented as an editor plugin (auto-shown on a page that has a backlink), allowing future improvements on its functionality or creating alternative backlinks by the community.

### Impact

Users who make connections between docs

### Additional Context

_No response_