* config: fix gesture dispatcher parsing with whitespaces
Some dispatcher functions (e.g., `moveFocusTo`) expect the given string to be
stripped of whitepsaces.
This fixes `gesture` line parsing: rather than calling dispatcher functions
with the original string, we reuse words parsed by `CConstVarList` and join
them with a comma.
* tests/gestures: Add a test for `movecursortocorner`
* config: Fix multi-argument gesture dispatchers parsing
The `dispatcher` gesture handler used to only handle
the first argument to the dispatcher, while some dispatchers
(e.g., `sendshortcut`) want multiple arguments.
This fixes `ConfigManager` to handle all the arguments
provided to the dispatcher gesture handler.
Fixes#11684.
* test/gestures: Add a test for a gesture with a multi-argument dispatcher
* test/gestures: Factor out `waitForWindowCount`
Reduce code duplication in the gestures test.
