bazel: `dev testlogic --files` is not as convenient as `make testlogic FILES`

With `make` I can do `make testlogic FILES="a b c"` (space-sparated)

`dev testlogic` does not recognize this.

I think it should -- none of the test files contain spaces, so it's not ambiguous.

The syntax should be a space-separated list of regular expressions.

Jira issue: CRDB-21115