refactor: unified configuration

[noomorph]

Description:

Prepares ground for landing #1910.

Slightly extends configuration capabilities, but the main point is that a configuration object for new Detox now contains all data it needs. No more scattering over places and files.

As a side effect, you can specify all that you previously could do via detox.init(config, userParams), but now those params reside also in package.json Detox's section, called behavior.

{
  "detox": {
    "behavior": {
      "init": {
        "reinstallApp": true,
        "launchApp": true,
        "exposeGlobals": true
      },
      "cleanup": {
        "shutdownDevice": false
      }
    },
  }
}

Also, this PR fixes a partially incorrect custom driver require logic, where it was not using process.cwd() to resolve relative path dependencies.

I plan to add the new config object extension to the markdown docs, and merge.

[coveralls]

Pull Request Test Coverage Report for Build 2136

• 79 of 82 (96.34%) changed or added relevant lines in 6 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.01%) to 76.926%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
detox/src/server/DetoxServer.js	8	11	72.73%

Totals
Change from base Build 1171:	0.01%
Covered Lines:	3196
Relevant Lines:	3866

---

💛 - Coveralls