Slow mode

This implements a slow mode, for setting a lower maximum azimuth speed in the case of high winds.

A new boolean command is added: slow_mode.

The command is only accepted if the azimuth is (almost) standing still. The new trace slow_mode_used shows whether the slow mode is active.

The control of the slow mode is implemented in the mech.html page.

The maximum azimuth speed in slow mode is hardcoded to be half of the normal maximum azimuth speed.

Notes from review by Paul:

• Remove 'bless test output' commit as it is unrelated
• rename slow_mode_used -> slow_mode_active
• rename max_v_fac -> max_v_factor
• log message should include deactivated or activated

changed target branch from jeroen to main

added 19 commits

• 39587a02...9a2de8f7 - 13 commits from branch main
• 631daf67 - Add slow_mode command and trace
• 9c85d3f7 - Add slow_mode input to spg3d
• 22c504ab - Add direct slow mode
• ef34076f - Implement logic for changing slow mode
• ef89ade1 - Use half speed in slow mode
• f05a9f42 - Add slow mode to mech.html

Compare with previous version

added 2 commits

• 619aade0 - Rename slow_mode_used -> slow_mode_active
• 0d755b73 - Rename max_v_fac -> max_v_factor

Compare with previous version

added 1 commit

• 2c38b093 - Clarify log message

Compare with previous version