PRO-6660: modules order

[myovchev]

Summary

Modules can now have a before: "module-name" property in their configuration to run (initialization) before another module. That works only for target modules that are initializable.

What are the specific steps to test this change?

// my-module/index.js
module.exports = {
  // will be initialized before the core image piece
  before: '@apostrophecms/image'
}

What kind of change does this PR introduce?

(Check at least one)

• Bug fix
• New feature
• Refactor
• Documentation
• Build-related changes
• Other

Make sure the PR fulfills these requirements:

• It includes a) the existing issue ID being resolved, b) a convincing reason for adding this feature, or c) a clear description of the bug it resolves
• The changelog is updated
• Related documentation has been updated
• Related tests have been updated

If adding a new feature without an already open issue, it's best to open a feature request issue first and wait for approval before working on it.

Other information:

[linear]

PRO-6660 Add a new optional before property to Apostrophe modules