This isn't a complete conversion to ErrorOr<void>, but a good chunk.
The end goal here is to propagate buffer allocation failures to the
caller, and allow the use of TRY() with formatting functions.
AK's version should see better inlining behaviors, than the LibM one.
We avoid mixed usage for now though.
Also clean up some stale math includes and improper floatingpoint usage.
Since strings don't have a constexpr constructor, these won't have any
effect anyways. Furthermore, this is explicitly disallowed by the
standard, and makes Clang tools freak out.
