npm-base: Add support for https proxy

[raymanfx]

npm was not picking up the environment variable, so we need to pass the flag before calling it.

[bachp]

Could you also implement it for http_proxy

[imyller]

Good point @bachp

Also the native variant should be patched similarly.

Could be done in the context of this PR or separately.

[bachp]

btw we already set some env variables via export. So for consistency reason we should set them all either via export or during the call.

[imyller]

I'd prefer the export method. There is slight difference in export and setting in call:

I'd assume export to stay set even if npm opens new (sub-)shell process while in-call might be limited to npm process itself but might not always propagate to it's sub-shells.

[raymanfx]

Updated:

• http/https support
• export variables
• support native targets as well, not only cross-compiling ones

[imyller]

LGTM