Companion for Use proper bounded vector type for nominations #10601 (#4709)

* Fixing polkadot after subtrate changes
`MAX_NOMINATIONS` was changed to `MaxNominations`

* Fixing some more places

* Apply suggestions from code review

* update lockfile for {"substrate"}

Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
Co-authored-by: Shawn Tabrizi <shawntabrizi@gmail.com>
Co-authored-by: parity-processbot <>