Refactor settings system with type-safe configuration and validation

[lauw]

Note: This PR depends on #160.

While looking at decimal support (#160) again, I noticed the settings types and validation could be cleaner (I'm not that familiar with TypeScript, so #160 didn't have proper type declarations). If you think this change is too big or doesn't make it clearer though, feel free to close it or suggest changes.

Changes:

• Split config types: CoilSettingConfiguration and HoldingRegisterSettingConfiguration for type safety
• Moved min/max validation from switch statement to config fields
• Added registerScale to separate input decimals from register multiplier
• Renamed decimalPrecision -> decimals

Example:

// Before
'temperatureTarget': { dataAddress: 135, decimalPrecision: 1, registerType: 'holding' }

// After  
'temperatureTarget': { dataAddress: 135, decimals: 1, registerType: 'holding', registerScale: 10, min: 10,
max: 30 }

[Jalle19]

Nice clean up, the whole AVAILABLE_SETTINGS has been there from the start and this software has grown in scope quite a lot since then, so it has become quite hairy.

[Jalle19]

Since both have dataAddress and registerType you could introduce a base interface that has these two fields, then use export interface HoldingRegisterSettingConfiguration extends BaseSettingConfiguration to add the rest of the fields

[lauw]

👍 I've updated it to use a base interface, thanks. Hopefully understood what you meant correctly.

[Jalle19]

Looks okay to me, let me test it locally before merging though

[Jalle19]

Works for me. The Home Assistant sensor only supports integer values still though, how exactly are you updating the temperature target value?

[lauw]

Works for me. The Home Assistant sensor only supports integer values still though, how exactly are you updating the temperature target value?

I can just manually set the state, or in my case I was setting it via automation:

The decimals just got stripped once it arrived to the bridge.