Berry improve persist dirty data handling

[s-hadinger]

Description:

Berry improve persist dirty data handling:

• persist module is unable to detect changes in sub-objects like lists or maps
• added persist.dirty() to indicate that data changed
• added persist.save(true) to force saving even if data is not marked as dirty

Related issue (if applicable): fixes #22187

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.2.7.8
• The code change is tested and works with Tasmota core ESP32 V.3.1.0.240926
• I accept the CLA.

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