BuiltIn: New Reset Log Level keyword for resetting the log level to the original value

[richardstone]

Opened this request after the discussion under #4919

I'd like to request adding a new keyword Reset Log Level that would always reset the log level to the one set with --loglevel argument to robot, or to INFO if not set.

It would ease the work as now if I want to revert to the previous log level after a Set Log Level keyword, I need to store the previous keyword in an extra variable.

[pekkaklarck]

Yeah, avoiding storing the previous level to a variable would be convenient in general and especially if the level is set and then reset in different keywords.

The only design question I see is should this keyword reset to the previous level or to the original level set using the --loglevel option. We could also support both with an optional argument. Or, possibly better, we could enhance the current Set Log Level keyword so that it accepts pseudo log levels PREVIOUS and ORIGINAL.

[pekkaklarck]

Being able to reset the level without storing the old value returned by Set Log Level is convenient because it allows setting the level in a setup and then resetting it in a teardown. I raised the priority accordingly and, because this is trivial to implement, added to RF 7.0 scope.

I decided to implement this so that Reset Log Level always resets the original level. If there are needs for setting the previous level, we can consider making the behavior configurable later.