feat(slider): incorrectly positioned label ie11

[Aleksandyr]

Closes #5210
Closes #4561

Additional information (check all that apply):

• Bug fix
• New functionality
• Documentation
• Demos
• CI/CD

Checklist:

• All relevant tags have been applied to this PR
• This PR includes unit tests covering all the new code
• This PR includes API docs for newly added methods/properties
• This PR includes feature/README.MD updates for the feature docs
• This PR includes general feature table updates in the root README.MD
• This PR includes CHANGELOG.MD updates for newly added functionality
• This PR contains breaking changes
• This PR includes ng update migrations for the breaking changes
• This PR includes behavioral changes and the feature specification has been updated with them

[Aleksandyr]

@simeonoff Could you please consider implementing additional classes for the label as it is handled as a separate component.

I assume that we need three more classes diversifying the left and the right label and it's active state as well.

[simeonoff]

@simeonoff Could you please consider implementing additional classes for the label as it is handled as a separate component.

I assume that we need three more classes diversifying the left and the right label and it's active state as well.

Added a new class for the label component. The classes are:

• FROM - igx-slider__label-from
• TO - igx-slider__label-to
• FROM ACTIVE - igx-slider__label-from--active
• TO ACTIVE - igx-slider__label-to--active

[Aleksandyr]

@simeonoff We have introduced the label as a separate component, now it only needs to be aligned and positioned correctly in IE11+