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 <[email protected]>
Co-authored-by: Shawn Tabrizi <[email protected]>
Co-authored-by: parity-processbot <>