Support relative paths to `node_modules` in the `reamppings.txt` files

[alcuadrado]

Describe the issue

Context

When the target of a reampping starts with node_modules/ we treat it as a special case, that will be resolved using the npm resolution rules. This is done here:

hardhat/v-next/hardhat/src/internal/builtin-plugins/solidity/build-system/resolver/remapped-npm-packages-graph.ts

Line 502 in f29d1d8

if (!target.startsWith("node_modules/")) {

Some projects have relative paths to those node_modules though, like ../../node_modules. See: #6994

Proposal

We should also support those, as they would still work using npm resolution rules.

Note that we shouldn't support any node_modules, but only the ones that are in the root of the project or a parent dir. For example:

• Accept: ./node_modules, ../node_modules, ../../node_modules, ../../a/../node_modules
• Ignore: ./something/node_modules — This node_modules WON'T be found by the npm resolution rules.