Having a capacity available is important for liquidity estimation.
* We add a dummy capacity to hop hints. Hop hints specify neither the
capacity nor a maxHTLC size, which is why we assume the channel to
have a high capacity relative to the amount we send.
* We add a capacity to local edges. These channels should always have a
capacity associated with them, even in the neutrino case (a fallback
to maxHTLC is not necessary). This is just for completeness, as the
probability calculation for local channels is done separately.
This commit adds the maximal capacity between two nodes to the unified
edge data. We use MaxHTLC as a replacement if the channel capacity is
not available.
In tests we use larger maxHTLC values to be able to convert to a
non-zero sat capacity.
This commit refactors the semantics of unified policies to unified
edges. The main changes are the following renamings:
* unifiedPolicies -> nodeEdgeUnifier
* unifiedPolicy -> edgeUnifier
* unifiedPolicyEdge -> unifiedEdge
Comments and shortened variable names are changed to reflect the new
semantics.
