fix(ui5-step-input): remove value rounding, apply value-state

[hinzzx]

Our <ui5-step-input> component used to round off the numbers based on the valuePrecision property. However this wasn't always the desired behavior.

For that reason we decided to give the application developers more control over the component and removed the rounding of the value if valuePrecision property is provided. To inform users about the correctness of their input based on the valuePrecision property, we now set a valueState on the component. This shows whether the input value meets the required precision.

Note: The valueState changing could be easily prevented by preventing the value-state-change event. For refference Check this PR

Closes: #8086