Berry 'tasmota.add_rule_once' and auto-remove rules with same pattern and id

[s-hadinger]

Description:

Enhancements to Berry rule handling:

• added tasmota.add_rule_once() for rules that are fired only once and automatically removed
• tasmota.add_rule() automatically removes any pre-existing rule if it has the same pattern and the same non-nil id. No changes is made to rules without id
• added simple unit test

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.3.1.1.250109
• I accept the CLA.

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