Berry added introspect.set() for class attributes

[s-hadinger]

Description:

Sync from Berry upstream berry-lang/berry#387

Make introspect.set() work with class attributes:

class A
    static var a
end

introspect.set(A, "a", 10)
# now A.a == 10

Checklist:

• The pull request is done against the latest development branch
• Only relevant files were touched
• Only one feature/fix was added per PR and the code change compiles without warnings
• The code change is tested and works with Tasmota core ESP8266 V.2.7.4.9
• The code change is tested and works with Tasmota core ESP32 V.2.0.14
• I accept the CLA.

NOTE: The code change must pass CI tests. Your PR cannot be merged unless tests pass