CSSTUDIO-3653 Linear Meter widget tooltip improvements

[abrahamwolk]

This pull request improves the tooltip of the Linear Meter widget by:

1. Overriding the method JFXBaseRepresentation.attachTooltip() in order to format the current value in a nicer way than the default. Before the changes in this PR, the current value was formatted in the following way:
   In contrast, with the change in this PR, the current value is formatted as follows:
2. Adding the widget property "Precision" to the Linear Meter widget, that allows one to specify the number of decimal places of the current value to display in the tooltip:
   

I have tested the improvements manually.

• Testing:

  • The feature has automated tests
  • Tests were run
  • If not, explain how you tested your changes

• Documentation:

  • The feature is documented
  • The documentation is up to date
  • Release notes:
    • Added an entry if the change is breaking or significant
    • Added an entry when adding a new feature

[sonarqubecloud]

Quality Gate failed

Failed conditions
18.2% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud

[abrahamwolk]

Quality Gate failed

Failed conditions 18.2% Duplication on New Code (required ≤ 3%)

See analysis details on SonarQube Cloud

This analysis seems incorrect to me: SonarQube says that the changes LinearMeterWidget.java are duplications, which they are, but they are also the standard way of implementing this kind of functionality, I believe.