Possible improvements for `Float.mo` (and `Int.mo`)

[luc-blaeser]

Possible areas of improvements for the Float.mo base library:

• isNaN() function is missing
• equal() and notEqual() comparisons should consider numerical errors, by requiring an epsilon argument.
• Positive infinity and negative infinity constants are missing.
• compare function does not have a total order and is inconsistent, e.g. compare(NaN, NaN) == #greater.
• neq function has a typo. Rename to neg. The same typo is in Int.mo.

Compiler issues detected while refactoring Float.mo:

• https://github.com/dfinity/motoko/issues/3646
• https://github.com/dfinity/motoko/issues/3647

Improvement for Int.mo base library:

• Fix typo in function name neq.

Update: Resolved in meantime:

• https://github.com/dfinity/motoko-base/pull/480
• https://github.com/dfinity/motoko-base/pull/479
• https://github.com/dfinity/motoko/pull/3676

Currently still open:

• Positive infinity and negative infinity constants are missing.
• https://github.com/dfinity/motoko/issues/3647