EKF2: use dedicated time-delay parameter

[bresch]

Requires:

• EKF2: migrate params to YAML #22982

Solved Problem

1. It is quite common to enable/disable an aiding source after takeoff to test the robustness of the system. With the current way of calculating the delayed time horizon, booting with or without an aiding source enabled leads to different results (especially for GNSS as it usually has the highest delay).
2. VIO systems are time-synchronized, meaning that their delay parameter is set to 0 but the actual delay is usually much higher, a known workaround is to set the VIO delay in the auxvel delay to size the buffer correctly.

Solution

Add EKF2_DELAY_MAX parameter to define the delay between the current time and delayed-time horizon.

Changelog Entry

For release notes:

New parameter: EKF2_DELAY_MAX
Documentation: TBD

Todo:

• bump EKF2_MAX_DELAY if smaller than sensor-specific delay

[bresch]

@dagar I added the param set to bump the max_delay and increased its default value to 200ms.