Communicate to a user they are a delegate

See [this discussion](https://github.com/liquidvotingio/decidim-module-liquidvoting/discussions/54)

A user presented with a Support/Delegate button for a Proposal should know if they are supporting/delegating only their own vote, or also on behalf of other(s) who have delegated to them.

There is a nuance here: when we present the user's "weight", we can speak of "direct" delegations (those delegations naming the user directly), or "full" delegations (considers not only the direct delegations, but all of the upstream delegations that resolve to the user).

If A and B both delegate to C, and C delegate to D, then using this language we can say D has a direct weight of 2 (C + D themself), or a full weight of 4 (we count A and B as well).

Direct is easier to calculate; full means reducing a graph of delegations from a relational store. For the user the semantics of the two may be different, and they may want to know just one or both.

This may be a feature to hide behind a config point.

This arguably should be presented only when non-zero.

Start with discussion #54 and trace the Support/Delegate button flow for proposals. Clarify whether the interface should show direct weight, full weight, or both, and whether this is configurable; done means the agreed information is shown only when non-zero.

Written by the indexing model from the issue text.