Support for Enclose/Confirm symbols introduced in WL 12.2

[gdelfino]

Is your feature request related to a problem? Please describe.
In version 12.2 of WL several symbols for were introduced for better handling/detection of failures. These are particularly useful for packages authors, the main audience of this plugin. This includes Enclose, Confirm, ConfirmAssert, ConfirmBy, ConfirmMatch and ConfirmQuiet. Usage of these symbols currently trigger the "could not resolve symbol definition" warning.

Describe the solution you'd like
No warning for usage of these built-in symbols.

Please also provide:

• OS: Windows 10
• IntelliJ IDEA 2021.2.1
• Wolfram Plugin Version 2021.2-beta-1