Add huffc support

[jtriley-eth]

Overview

Adds huff compiler support.

Additions

Adds a huff library and Huffc structure with the following fields:

• compilerPath: path of compiler (Default: huffc)
• filePath: path of input file (Required)
• outputPath: path of artifacts (Optional)
• mainName: name of alternate MAIN macro (Optional)
• constructorName: name of alternate CONSTRUCTOR macro (Optional)
• onlyRuntime: if true, only the runtime bytecode will be returned (Default: false)
• constantOverrides: list of key value pairs in the format "<constant_name>=<hex_literal>"

Setting any value may be done via a set<Field> API and adding values to lists may be done via an add<Field> API.

Can be run directly via compile or converted to a Command via toCommand methods.

huff.create()
    .setCompilerPath("diffhuff")
    .setFilePath("./filePath.huff")
    .setOutputPath("./outputPath.json")
    .setMainName("ALT_MAIN")
    .setConstructorName("ALT_CONSTRUCTOR")
    .setOnlyRuntime(true)
    .addConstantOverride("SLOT", SLOT)
    .addConstantOverride("OTHER_SLOT", OTHER_SLOT)
    .compile();

Added documentation, reference, and github action to run huff compilation tests.