[camera] Remove OCMock from CameraSettingsTests, CameraMethodChannelTests and CameraSessionPresetsTests

[mchudy]

Continuation of OCMock removal from tests related to flutter/flutter#119109.

• Introduces new protocols: FLTFrameRateRange and FLTCaptureDeviceFormat
• Refactors CameraTestUtils to get rid of multiple similar helper methods in favor of using FLTCamConfiguration to set up mocks in tests. Also removes some OCMock usage from there.

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[stuartmorgan]

LGTM with a few minor comments.

[stuartmorgan]

(That was meant to be an actual LGTM approval.)