CgSpringVariableConstructor refactoring

[tepa46]

Description

Closed #2326

FieldManagerFacade was created for more convenient processing injectingMockFields, mockedFields, autowiredFields.

FieldManagerFacade uses 3 managers: CgInjectingMocksFieldsManager, CgMockedFieldsManager, CgAutowiredFieldsManager for processing each type of fields.

How to test

Manual tests

Manually tested on spring-boot-testing, spring-petclinic and a project that does not use Spring framework.

Self-check list

• I've set the proper labels for my PR (at least, for category and component).
• PR title and description are clear and intelligible.
• I've added enough comments to my code, particularly in hard-to-understand areas.
• The functionality I've repaired, changed or added is covered with automated tests.
• Manual tests have been provided optionally.
• The documentation for the functionality I've been working on is up-to-date.