If invalid value is set for a property in `settings.properties`, default value should be applied

[alisevych]

Description

If invalid value is set for a property in settings.properties, default value should be applied.
Currently: the following line is added to settings.properties:
useFuzzing=trueeee

• and Fuzzing is disabled on UI

To Reproduce

1. Install one of the latest plugin's builds from main, build used
2. Add the following line to settings.properties:

useFuzzing=trueeee

3. Restart IDEA
4. Run the 'UTBotJava' project
5. Open File -> Settings -> Tools -> UnitTestBot

Expected behavior

useFuzzing is true by default
So Fuzzing-Symbolic slider should be enabled

Actual behavior

Fuzzing is disabled.

Visual proofs (screenshots, logs, images)

Environment

Windows 10 Pro
IntelliJ IDEA 2022.2.3

Additional context

Found during manual testing of

• Self-documenting settings template #1420