* sort snap trienode heal requests

* eth/protocols/snap: remove debug code

* eth/protocols/snap: simplify sort, generate pathsets later

* eth/protocols/snap: review concern

* eth/protocols/snap: renamings

* eth/protocols/snap: add comments in Merge

* eth/protocols/snap: remove variable 'last' in Merge

* eth/protocols/snap: fix lint flaws in test
Co-authored-by: Felix Lange <fjl@twurst.com>