Warning about update rates

[peterbrightwell]

(From workshop 2024-07-02)

If annotations are stored in NVRAM then this could cause premature failure if excessive updates (which could be as low as in the hundreds).

Control systems are not expected to push say multiple updates per day.

Add warning text to spec to advise accordingly.

Also consider a flag to indicate if it's ok to accept frequent annotations. This shouldn't be required for current use scenarios but perhaps in the future could be useful.

This could be an int (what size?) that is decremented each time there's a write. Or in the case of something unlimited, don't decrement it, or just don't specify it (default no limit). It will need a new param reg tag. It is up to IS-13 implementers to put it in if they have limits.

Given that we just say 500 error for sizes/numbers exceeded, probably just do the same here. With helpful text.