Enhance workload module base class with "auto-build"

[aklenik]

Context

Building on #857 and #858 (and extending #576), the base class implementation of workload modules could be smarter.
Currently, this idea is only meaningful for workload modules that submit a single TX when enabled (so no batches).

Expected Behavior

Based on a schema like this:

workload:
    module: mySimpleWorkload.js
    arguments: 
        myArg1: value1
        builder: # special, reserved argument name for the base class
            targetContract: myContractID
            targetFunction: transfer
            arguments:
            - name: source
              value: account1
              # values could reference arguments above using YAML anchors and aliases
            - name: target
              value: account2
            - name: amount
              value: 100
            timeout: 5000
            # ...

a smarter workload module base class could be implemented that can partially/completely build a TX. In this case, reusing a builder instance is definitely a good idea.

Your Environment

• Version used: v0.3.1