feat: support loading types from ethPM Manifest

[fubuloubu]

What I did

Allow loading ABI types from ethPM manifest files

How I did it

Hacking

How to verify it

The whole imports system needs a lot of work

Description for the changelog

Load interfaces from an ethPM Manifest file

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[codecov-commenter]

Codecov Report

Merging #2628 (f866687) into master (82f44ee) will decrease coverage by 0.24%.
The diff coverage is 21.05%.

@@            Coverage Diff             @@
##           master    #2628      +/-   ##
==========================================
- Coverage   86.55%   86.30%   -0.25%     
==========================================
  Files          92       92              
  Lines        9460     9494      +34     
  Branches     2400     2415      +15     
==========================================
+ Hits         8188     8194       +6     
- Misses        781      805      +24     
- Partials      491      495       +4     

Impacted Files	Coverage Δ
vyper/cli/vyper_compile.py	68.70% <0.00%> (-3.88%)	⬇️
vyper/cli/vyper_json.py	79.78% <23.07%> (-5.65%)	⬇️
vyper/cli/utils.py	88.09% <50.00%> (-4.02%)	⬇️

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[charles-cooper]

also maybe add a test

[fubuloubu]

Tested locally by using Brownie (which uses JSON mode to compile) and downloaded copy of OpenZeppelin/openzeppelin-contracts converted to ethPM manifest format (using Ape)

[fubuloubu]

Like to note this code is really hacky and should be refactored so it finds the different types of interfaces faster:

from location import Bar  # can either be `location/Bar.{vy|json}` or `location.json:Bar`