breaking: updates to ember 5.3 - drops Ember 4.4

[Pixelik]

Resolves adopted-ember-addons#733

Chore

• runs ember-cli-update --to 5.3
• updates to ember-data 5.3
• runs yarn & updates yarn.lock
• installs babel-plugin-dynamic-import-node
  • otherwise the ember 4.x test scenarios throw Error
• sets stylelint to target .scss files
• runs yarn lint:fix
• fixes stylelint errors
• installs @babel/plugin-proposal-private-property-in-object
  • otherwise ember s throws Error
• installs @ember/string

Refactor

• replaces PromiseManyArray.filter with PromiseManyArray.content.filter
  • because PromiseManyArray.filter no longer exists in Ember 5
• stops using A() with PromiseManyArray
  • as it is no longer allowed in Ember 5
• increases later() timeout for some tests
  • otherwise the following tests sometimes fail:
    • Integration | Validations | Factory - General: debounced validations
    • Integration | Validations | Factory - General: debounced validator should only be called once
• refactors isDescriptor() logic & syntax
  • otherwise the embroider test scenarios are failing

Breaking

• drops support for Ember 4.4
  • because we only support the last 2 LTS version anyway & because the relevant Ember 4.4 test scenario throws Error: required module @ember/renderer is missing
• drops support for Node v14

Tasks:

• Added test case(s)
• Updated documentation