gst: Add GstQueryLatency handling

[TIS-Edgar]

Define maximum latency and GST_CLOCK_TIME_NONE to prevent timeouts.

Potential fix for #528.

All gstreamer sources must be synchronized with the gstreamer clock.
Since aravissrc is a live source it can't give reliable increasing timestamps and instead works with durations.
Ideally that would mean first timestamp (0) + duration of frame. New timestamp + duration of frame, etc.
Since we cannot know what the duration of a frame is (some come faster, some slower, thus never being 100% accurate) gstreamer wants to know a latency range.
This patch defined the latency as min=framerate and max=GST_CLOCK_TIME_NONE.
That basically says expect the next buffer between average duration and any given time in the future after that,
users more than enough time to trigger, extended exposure times, etc.

[TIS-Edgar]

I have no clue why the Aravis-MSVC check fails with

source_subfolder\meson.build:291:0: ERROR: Dependency 'glib-2.0' is required but not found.

[EmmanuelP]

I have no clue why the Aravis-MSVC check fails with

source_subfolder\meson.build:291:0: ERROR: Dependency 'glib-2.0' is required but not found.

Don't worry about that, this pipeline is failing for a while now, probably due to a change in the build environment.

[EmmanuelP]

Thanks Edgar