Introduce parameters and placeholders

[abdala]

Single parameters:

{
  parameters: {
    a: 'b',
    b: '${a}',
    c: {
      d: 'e'
    }
  },
  name: 'Test 1',
  act: {
    import: 'syncFunction',
    from: 'functions.js',
    arguments: [
      {a: '${a}', d: '${c.d}'},
    ],
  },
  assert: {
    a: '${b}',
  },
}

Or multiple paramters:

{
  name: 'Test 2',
  parameters: [
    {a: 'b', b: '${a}'},
    {a: 'c', b: '${a}'},
  ],
  act: {
    import: 'syncFunction',
    from: 'functions.js',
    arguments: [{a: '${a}'}],
  },
  assert: {
    a: '${b}',
  },
}