Support for the deployed bytecode (.bin-runtime)

[vasemkin]

Description

This pull request adds an option to export the deployedBytecode artifact (.bin-runtime).

An includeDeployed option is added, which spawns a deployed/ folder inside the output directory.

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

Checklist:

• I have tested my code in a separate Hardhat environment
• My code follows the style guidelines of this project
• I have performed a self-review of my code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have commented my code, particularly in hard-to-understand areas

[ItsNickBarry]

If we're going to support both initcode and runtime code, I think we should treat them as separate outputs of equal significance. That is, we should not nest the runtime code folder inside of the existing output folder.

Two ways to do this:

1. output to separate folders (./init_bytecode/ and ./deployed_bytecode/)
2. output to the same folder, and add a suffix to each file (./bytecode/Contract__init.bin and ./bytecode/Contract__deployed.bin)

The first option would require duplicating the path option.

Then, I'd like to replace the includeDeployed option with its inverse, for each output type: skipInitBytecode and skipDeployedBytecode. These would default to false.

We could go further, and duplicate most of the existing configuration options so that they can be set separately for each output type, but I think that might be excessive.

What do you think?