Add additional key checks for KV

[darkwatchuk]

Observed behavior

Adding a key/pair to a bucket with more than one consecutive dot in the key results in a "no response from stream" exception and is confusing. e.g. default..foobar

Expected behavior

If this format of key is not valid, then an appropriate more informative key format exception or similar should be raised.

Server and client version

Server 2.10.16
.NET Client 2.3.2

Host environment

No response

Steps to reproduce

No response

[mtmk]

we have validation I believe based on ADR-8 but this case might not have been covered cc @scottf