HTTP(S)/2 Support

[ashubham]

Is your feature request related to a problem? Please describe.
Using Http2 in Dev mode will make the application load faster as it removes the "6 concurrent requests" limit from the browser and makes each request faster as it uses connection pooling.

Describe the solution you'd like
Instead of node http/https packages, use the http/2 package and options.

A similar solution is already implemented by Snowpack for example:
FredKSchott/snowpack#399

Describe alternatives you've considered
Snowpack is an alternative, but I want to stick to using Rollup in Prod.

[yyx990803]

We already have https support... turns out we didn't think of making it http2 by default 😅