feat: add sentinel and remove data source for consideration

[matt-FFFFFF]

Added new way to deploy sentinel - in future we can remove the solution way.

Also removed data source, can't see it's necessary really. If the RG doesn't exist it'll fail anyway.

[jaredfholgate]

@matt-FFFFFF A few questions on this. The security insights solution needs to be retained? If so we need to use a different solution as removed does not support an index. You can use a moved and removed together to achieve as far as I can tell. E.g.

moved {
  from = foo.bar["abc"]
  to   = foo.bar_abc
}
removed {
  from = foo.bar_abc
  lifecycle {
    destroy = false
  }
}

[jaredfholgate]

The log_analytics_workspace_cmk_for_query_forced variable defaults to null, so wondering how that might impact the azapi sentinel resource?