* Renaming androgynous sub-object names according to where they belong
why:
These objects are not explicitly dealt with. They give meaning to
some generic wrapper objects. Naming them after their origin may
help troubleshooting.
* Redefine proof nodes list data type for `snap/1` wire protocol
why:
The current specification suffered from the fact that the basic data
type for a proof node is an RLP encoded hexary node. This slightly
confused the encoding/decoding magic.
details:
This is the second attempt, now wrapping the `seq[Blob]` into a
wrapper object of `seq[SnapProof]` for a distinct alias sequence.
In the previous attempt, `SnapProof` was a wrapper object holding the
`Blob` with magic applied to the `seq[]`. This needed the `append`
mixin to strip the outer wrapper that was applied to the `Blob` already
when it was passed as argument.
* Fix some prototype inconsistency
why:
For easy reading, `getAccountRange()` handler return code should
resemble the `accoundRange()` anruments prototype.