rtla/timerlat: Add continue action

rtla/timerlat: Add continue action

Introduce option to resume tracing after a latency threshold overflow.
The option is implemented as an action named "continue".

Example:
$ rtla timerlat top -q -T 200 -d 1s --on-threshold \
exec,command="echo Threshold" --on-threshold continue
Threshold
Threshold
Threshold
                                     Timer Latency
...

The feature is supported for both hist and top. After the continue
action is executed, processing of the list of actions is stopped and
tracing is resumed.

Cc: John Kacur <jkacur@redhat.com>
Cc: Luis Goncalves <lgoncalv@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Chang Yin <cyin@redhat.com>
Cc: Costa Shulyupin <costa.shul@redhat.com>
Cc: Crystal Wood <crwood@redhat.com>
Cc: Gabriele Monaco <gmonaco@redhat.com>
Link: https://lore.kernel.org/20250626123405.1496931-5-tglozar@redhat.com
Signed-off-by: Tomas Glozar <tglozar@redhat.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>