Revert "Enable custom colors for all numeric values (also outside of 0-100 range)"

[maxwroc]

Reverts #599

Merged it too fast... now when looked at the full code:

• There is a condition below which checks whether the step value is greater than 100. So if you have a different color for 500 and 1000 it won't work. The only reason why it didn't fail in the test is that the additional step/color was missing (between 100 and 1000)
  https://github.com/maxwroc/battery-state-card/blob/3bae17c6bf67fddbb958ad4098d74b75b8426eb3/src/colors.ts#L30C48-L30C67
• If the gradient flag is true then it will fail as well - the getColorInterpolationForPercentage requires number in 0-100 range

[coveralls]

Pull Request Test Coverage Report for Build 6897057243

• 1 of 1 (100.0%) changed or added relevant line in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.09%) to 80.605%

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Totals
Change from base Build 6896405551:	-0.09%
Covered Lines:	329
Relevant Lines:	392

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💛 - Coveralls