Refine existing checks

[intarga]

• fix monotonic_increase_check based on Øystein's feedback
• implement monotonic_increase_check_cache
• better structure for min_less_than_single etc. 3 checks instead of 4
• individual flags for the above consistency checks
• come up with an equivalent to DataCache for consistency checks
• make cache versions of existing consistency checks

[Lun4m]

Last minor formatting stuff I noticed. Also, it might be useful to implement Ord for Flags (in the future), it could simplify the flag coalescing part of the code?

[intarga]

Also, it might be useful to implement Ord for Flags

It's tempting, but are we sure the precedence order for coalescing will always be the same?

[Lun4m]

No, that's why I said in the future :) However, having checks implementing different flag precedence doesn't sound right?

[intarga]

No, that's why I said in the future :) However, having checks implementing different flag precedence doesn't sound right?

I could imagine a check that looks for a success condition instead of a fail condition having a different order, idk if that will happen in practice though