Support KString in entity name

[maxwroc]

This way we will be able to use dynamic values in entity.name configuration.

e.g.

- entity: sensor.my_battery
  name: "My Battery ({sensor.my_battery_type.state})"

The above can print for example "My Battery (CR2032)" as the entity name

[coveralls]

Pull Request Test Coverage Report for Build 7278574184

• 3 of 3 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.05%) to 80.658%

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Totals
Change from base Build 7240946763:	0.05%
Covered Lines:	331
Relevant Lines:	394

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💛 - Coveralls

[maxwroc]

#608