Find and replace all nolint instances refering to the `lll` linter and
replace with `ll` which is the name of our custom version of the `lll`
linter which can be used to ignore log lines during linting.
The next commit will do the configuration of the custom linter and
disable the default one.
In this commit, we update an existing migration which at the time of
writing has not been included in a release. We update it so that it
converts the format used for MissionControl result encoding to use pure
TLV instead. The 3 structs that have been updated are: `mcHop`,
`mcRoute` and `paymentResult`.
Add a new mcRoute type that houses the data about a route that MC
actually uses. Then add a migration (channeldb/migration32) that
migrates the existing store from its current serialisation to the new,
more minimal serialisation.
