v2: Restrict ECDSA verify to compact or DER verification without flag

[DavidBuchanan314]

Per the comment here:

https://github.com/paulmillr/noble-curves/blob/fb02e93ff66ecd7bc7257d8f76e6cdf88b54bfa9/src/abstract/weierstrass.ts#L1053-L1060

A signature of one type can be trivially transformed into the other (much like low-s vs high-s).

Perhaps this is the intended behaviour - if so, I think it should be documented much more explicitly