equality of ideals over different rings

These two are surprisingly annoying:
```m2
i1 : ideal 0 == 0 * ideal vars(QQ[x])
stdio:1:10:(3): error: expected ideals for the same ring

i2 : ideal 1 == ideal 1_(QQ[x])
stdio:2:9:(3): error: expected ideals for the same ring
```

Can we have comparison of ideals over different rings to give false, unless one is ZZ, then use `Ideal == ZZ`?

No files or tests are named. Start by locating the equality implementation and existing tests for ideals, then reproduce the two examples in the issue. Done means comparisons between ideals from different rings return false, while the specified comparison with ZZ follows the requested behavior, with regression coverage for both cases.

Written by the indexing model from the issue text.