fix: remove BASEDRIVER_HANDLED_SETTINGS since no longer exists in the base driver

[KazuCocoa]

I noticed the BASEDRIVER_HANDLED_SETTINGS is no longer in the base driver since the settings are in images plugin. appium/appium#16368

So, this driver no longer needs BASEDRIVER_HANDLED_SETTINGS for now, which is driver based settings.
UIA2 driver only has plugins for the uia2 server one.

For example, test failures in https://dev.azure.com/AppiumCI/Appium%20CI/_build/results?buildId=19412&view=results (to use appium 2.0 as its test) failed by this undefined BASEDRIVER_HANDLED_SETTINGS

[mykola-mokhnach]

AFAIK this change was done because uia2 throws an exception if an unknown setting name is supplied (which is the case while supplying image-related settings). I'm not quite sure how that is supposed to work now. @jlipps could you please provide more details?

[KazuCocoa]

ah.. i see. I tested with below:

@driver.update_settings(
          {
            defaultImageTemplateScale: 4,
            imageMatchThreshold: 0.9,
            actionAcknowledgmentTimeout: 200
          }
        )

Then, only actionAcknowledgmentTimeout should be applied if no images plugin.
This PR returns an error. #499 did not apply all of them.

So, we need to update the server side to apply acceptable settings only in this case like xcuitest driver since we should expect other plugins also have their own settings apis.

[KazuCocoa]

ah, maybe this change + server-side change to apply acceptable settings only as same as xcuitest-driver...?

[KazuCocoa]

mm, no. The xcuitest-driver is still v1's base driver. So anyway this change and #499 are not enough.