[MAJOR] Add special type of links using the PROPERTIES drawer

[lytex]

Have you checked whether this feature is not already on the project board?

Yes

Is your feature request related to a problem? Please describe.
I want to give semantic meaning to the links. For example, if I'm joining a big, existing team, I want to create relationships like "John is Mike's boss" and "Angela works with Peter", and visualize these relationships (for example by coloring each type of link with a different type of color) so that the organizational chart emerges from individual links
Another use case is visualize a set of tasks and their dependencies

Describe the solution you'd like
As per this org-roam issue links inside an PROPERTIES drawer will not be considered as backlinks, which makes them perfect to declare a new type of link/backlink independent from all the other regular links
I think that coloring each type of link with one color and maybe using the same color for all nodes is a good starting point, another interesting implementation is drawing a small box with the type of relationship (see, for example trillium implements multiple types of links)

[shunlog]

@lytex I think this is the relevant discussion: #25. If you agree, maybe close the issue?

[lytex]

Yes, it's the same discussion, however this implementation is significantly different from the other one.
I'm closing this issue and doing a comparison in #25