Two-directional transformations

[MateuszKubuszok]

• [x] define Iso
• [x] define Codec
• [x] ~automatic derivation in AutoDerived companions~ after consideration - it is not needed
• [x] ~automatic derivation in chimney.auto~ after consideration - it is not needed
• [x] define
  • [x] withFieldRenamed
• [x] extract total/partial from Iso/Codec
• [x] tests
• [x] documentation

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 97.46835% with 4 lines in your changes missing coverage. Please review.

Project coverage is 88.10%. Comparing base (a5c1e13) to head (bc4febd).

Files	Patch %	Lines
...nal/compiletime/derivation/codec/CodecMacros.scala	96.77%	1 Missing :warning:
...nternal/compiletime/derivation/iso/IsoMacros.scala	96.77%	1 Missing :warning:
...nal/compiletime/derivation/codec/CodecMacros.scala	96.77%	1 Missing :warning:
...nternal/compiletime/derivation/iso/IsoMacros.scala	96.77%	1 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #547 +/- ## ========================================== + Coverage 87.98% 88.10% +0.11% ========================================== Files 138 148 +10 Lines 5536 5683 +147 Branches 470 475 +5 ========================================== + Hits 4871 5007 +136 - Misses 665 676 +11 ```

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