Delete operator

[philrz]

As this issue is being filed, Zed is at commit 4530c31.

Now that #3992 has been completed, deletion of data is possible with just a filter expression. This would make it easier to support deletion via an operator in the Zed query language rather than just via the API and zed CLI commands as it's done currently.

Indeed, a community user did ask about this in a public Slack thread. Some excerpts of their reaction after being pointed at the CLI:

is there a way to do a delete in a query itself for eg from in zui? it's just easier to stay in zui most times