Mongoose library update and improvements to HTTP client/server

[aufau]

First commit Update mongoose to version 7.13 with minimal changes is simply mongoose library update with as little changes as possible.

Following commits are improvements, bugfixes, rewrites and features.

[entdark]

Will this work out of the box and we don't need to install anything?

[aufau]

Will what work out of the box, mongoose and http downloads? Yes, we've used mongoose library since the beginning. It's built-in: https://github.com/mvdevs/jk2mv/blob/master/libs/mongoose/mongoose.c There is no new functionality in this PR so far, only library update and some small improvements.