[ISUEE-3578][Improve] Merge dev-2.1.3 Docker & Email BackedEnd Improve Into dev

[zzzk1]

What changes were proposed in this pull request

Link:#3578

In fact, in the dev-2.1.3 branch, the Setting module's front-end and back-end improvements have been completed, and this PR will introduce the improved back-end code.

Brief change log

Verifying this change

This change added tests and can be verified as follows: -SettingServiceTest

Does this pull request potentially affect one of the following parts

• Dependencies (does it add or upgrade a dependency): (no)

[wolfboys]

Is there no Front-End code submitted in this PR? 🤔