Revert "chore(amd): added tests for AMD module registering and loading"

This reverts commit 89ed983f5b7d0190d76f838742dc571bcd72936d.
Revert "fix(amd): removed elgg_require_js for backwards compatibility"

This reverts commit 76584089bee2b3246c736edb6b250e149acf906f.

Conflicts:
	engine/lib/views.php
Revert "Fixes #5090: Possible to register js as shimmed AMD module"

This reverts commit 4dcaf3889c1800ea879db1606f7883a21edf3a6f.

Conflicts:
	engine/classes/Elgg/AmdConfig.php
	engine/tests/phpunit/Elgg/Amd/ConfigTest.php
fix(js): Separated elgg_load_js() and elgg_define_js().

Refs #6603, #6497, #5090.
docs(amd): Separated design and guides for AMD docs.

Refs #6603, #6497, #5090.
Merge pull request #6782 from brettp/revert_6497

Revert 6497