Add: Helper Cards for the charging configuration

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THEN:

• read charging configuration and provide the config as tokens
• Active power limits
• Deactivate power limits

AND:

• max charging limit is higher than
• max discharging limit is higher then
• max charging limit is active
• max discharging limit is active
• any limit on the charging system is active

WHEN:

• max charging limit changed
• max discharging limit changed

ALL CARDS

• add hints as documentation

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implemented in 0.6.0