Allow importing type and capability values

[dsainati1]

Closes #491, #712

Description

This does two primary things:

1. Change the representation of types in cadence.TypeValue and cadence.Capability to be a cadence.Type instead of a string. This also requires implementation of encoding and decoding types to and from JSON.

2. Implement ImportType to convert a cadence.Type into a interpreter.StaticType

3. Update importing to allow for the importing of capability and type values

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• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[turbolent]

Nice work!

[codecov-commenter]

Codecov Report

Merging #1202 (bec485a) into master (d138ccf) will increase coverage by 0.23%.
The diff coverage is 82.57%.

❗ Current head bec485a differs from pull request most recent head 314f5fa. Consider uploading reports for the commit 314f5fa to get more accurate results

@@            Coverage Diff             @@
##           master    #1202      +/-   ##
==========================================
+ Coverage   77.18%   77.41%   +0.23%     
==========================================
  Files         273      273              
  Lines       34209    34726     +517     
==========================================
+ Hits        26403    26882     +479     
- Misses       6736     6768      +32     
- Partials     1070     1076       +6     

Flag	Coverage Δ
unittests	77.41% <82.57%> (+0.23%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
runtime/sema/type.go	87.92% <ø> (+0.12%)	⬆️
encoding/json/decode.go	73.18% <62.10%> (-7.64%)	⬇️
types.go	74.19% <71.42%> (+16.46%)	⬆️
runtime/interpreter/interpreter.go	89.03% <77.77%> (+0.11%)	⬆️
runtime/interpreter/statictype.go	69.86% <78.78%> (+0.96%)	⬆️
runtime/convertTypes.go	79.15% <97.61%> (+17.25%)	⬆️
encoding/json/encode.go	93.42% <98.40%> (+2.30%)	⬆️
runtime/convertValues.go	76.60% <100.00%> (+1.43%)	⬆️
runtime/interpreter/dynamictype.go	68.57% <100.00%> (+5.71%)	⬆️
runtime/interpreter/value.go	82.41% <100.00%> (+0.22%)	⬆️
... and 8 more

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[turbolent]

Nice work also adding support for importing capabilities

[SupunS]

Looks good!

Shall we also address this TODO and the one below that: convertValues_test.go#L1840-L1841
This was added earlier when we didn't have the type/capability importing support.

[turbolent]

Looks good! The PR is only missing some type conversions, which could also be done in a follow up PR, and some of Supun's suggestions are still open

[turbolent]

@dsainati1 This looks like it is working now, but I still suggest applying Supun's code formatting suggestions. We try to keep lines short for readability reasons