feat: remove node-fetch from lib

[mlecoq]

I'd like to use this lib on an edge environment (Vercel) and node-fetch has incompatible dependencies

The goal of this pr is to use node / edge built-in fetch

[valeriansaliou]

I’d like to keep support for legacy NodeJS versions in this library, if possible down to 12 or 14 since it’s still being used in legacy Node production systems, wouldn’t there be a way to selectively import node-fetch for environments that do not have native fetch?

[adrai]

https://github.com/lquixada/cross-fetch

[mlecoq]

Could we just create a new major version ?

For older versions of node, people could still use previous version of the lib

Node v22 has just arrived, node 18 is in lts

[mlecoq]

Hi @valeriansaliou , I have updated the PR to use cross-fetch as suggested by @adrai and updated minimum node version to 14 (cross-fetch has dropped support for 10 and 12)