tt CLI (2.11): `tt rs vs bootstrap` with more informative error

[TarantoolBot]

Product: tt CLI
Since: tt 2.11.0
Dev ticket:
Root document: https://www.tarantool.io/en/doc/latest/tooling/tt_cli/replicaset/#tt-replicaset-vshard-bootstrap

SME: @ AlexandrLitkevich @ oleg-jukovec @ elhimov

Details

Make more informative error when trying to launch tt rs vs bootstrap
against cluster where no sharing roles configured (for example when
launched against non-vshard cluster).
Requested by @elhimov in tarantool/tt@350bf7c.

[Totktonada]

tt rs vs bs would sound more funny :)