buffer: move c++ float functions to js

This ports the Buffer#write(Double|Float)(B|L)E functions to JS.
This fixes a security issue concerning type confusion and fixes
another possible crash in combination with `noAssert`.
In addition to that it will also significantly improve the write
performance.

Fixes: https://github.com/nodejs/node/issues/12179
Fixes: https://github.com/nodejs/node/issues/8724

PR-URL: https://github.com/nodejs/node/pull/18395


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>