build(docgen): fixes docgen module usage failing on Windows platform

[ypbnv]

JIRA: https://jira.appcelerator.org/browse/TIMOB-27388

Description:
Reworks the calling of titanium-docgen generation and validation due to child process spawning being
broken on Windows. It ignores the shebang script and fails to initialize the called module. So instead we are manually calling the generated binary for Windows.

Thanks, @ewanharris and @janvennemann, for helping me deal with this!

[build]

	Fails
🚫	Tests have failed, see below for more information.

	Messages
📖	💾 Here's the generated SDK zipfile.
📖	❌ 1 tests have failed There are 1 tests failing and 471 skipped out of 4336 total tests.
📖	✊ The commits in this PR match our conventions! Feel free to Rebase and Merge this PR when ready.

Tests:

Classname	Name	Time	Error
ios.os	#cpus() returns array of objects whose length matches Ti.Platform.processorCount	0	Error: undefined is not an object (evaluating 'modelAndSpeed[0]') file:///Users/build/Library/Developer/CoreSimulator/Devices/0A9B4819-1106-4A71-A77A-2A6805A5EB32/data/Containers/Bundle/Application/85990C50-CCF5-4E21-838A-9B169EEB2445/mocha.app/ti.main.js:7311:29 file:///Users/build/Library/Developer/CoreSimulator/Devices/0A9B4819-1106-4A71-A77A-2A6805A5EB32/data/Containers/Bundle/Application/85990C50-CCF5-4E21-838A-9B169EEB2445/mocha.app/os.test.js:65:25 file:///Users/build/Library/Developer/CoreSimulator/Devices/0A9B4819-1106-4A71-A77A-2A6805A5EB32/data/Containers/Bundle/Application/85990C50-CCF5-4E21-838A-9B169EEB2445/mocha.app/ti-mocha.js:4376:41 file:///Users/build/Library/Developer/CoreSimulator/Devices/0A9B4819-1106-4A71-A77A-2A6805A5EB32/data/Containers/Bundle/Application/85990C50-CCF5-4E21-838A-9B169EEB2445/mocha.app/ti-mocha.js:4763:17 file:///Users/build/Library/Developer/CoreSimulator/Devices/0A9B4819-1106-4A71-A77A-2A6805A5EB32/data/Containers/Bundle/Application/85990C50-CCF5-4E21-838A-9B169EEB2445/mocha.app/ti-mocha.js:4840:23 next@file:///Users/build/Library/Developer/CoreSimulator/Devices/0A9B4819-1106-4A71-A77A-2A6805A5EB32/data/Containers/Bundle/Application/85990C50-CCF5-4E21-838A-9B169EEB2445/mocha.app/ti-mocha.js:4688:20 file:///Users/build/Library/Developer/CoreSimulator/Devices/0A9B4819-1106-4A71-A77A-2A6805A5EB32/data/Containers/Bundle/Application/85990C50-CCF5-4E21-838A-9B169EEB2445/mocha.app/ti-mocha.js:4698:15 next@file:///Users/build/Library/Developer/CoreSimulator/Devices/0A9B4819-1106-4A71-A77A-2A6805A5EB32/data/Containers/Bundle/Application/85990C50-CCF5-4E21-838A-9B169EEB2445/mocha.app/ti-mocha.js:4636:30 file:///Users/build/Library/Developer/CoreSimulator/Devices/0A9B4819-1106-4A71-A77A-2A6805A5EB32/data/Containers/Bundle/Application/85990C50-CCF5-4E21-838A-9B169EEB2445/mocha.app/ti-mocha.js:4665:13 timeslice@file:///Users/build/Library/Developer/CoreSimulator/Devices/0A9B4819-1106-4A71-A77A-2A6805A5EB32/data/Containers/Bundle/Application/85990C50-CCF5-4E21-838A-9B169EEB2445/mocha.app/ti-mocha.js:5764:29

Generated by 🚫 dangerJS against ec57e26

[ewanharris]

Looks good to me!