test_runner: improve wait_until (#9936)

Improves `wait_until` by:

* Use `timeout` instead of `iterations`. This allows changing the
timeout/interval parameters independently.
* Make `timeout` and `interval` optional (default 20s and 0.5s). Most
callers don't care.
* Only output status every 1s by default, and add optional
`status_interval` parameter.
* Remove `show_intermediate_error`, this was always emitted anyway.

Most callers have been updated to use the defaults, except where they
had good reason otherwise.

test_runner/regress/test_readonly_node.py

@@ -215,8 +215,6 @@ def test_readonly_node_gc(neon_env_builder: NeonEnvBuilder):
 
         # wait for lease renewal before running query.
         _, offset = wait_until(
-            20,
-            0.5,
             lambda: ep_static.assert_log_contains(
                 "lsn_lease_bg_task.*Request succeeded", offset=offset
             ),