[Feature]: support shiny.fluent report style

[nbbn]

Guidelines

• I agree to follow this project's Contributing Guidelines.

Description

There is public demo using shiny.fluent.
For many people, this means it is supported by package.
My suggestion is to add support for it in data.validator.

Problem

I saw fluent report made with data.validator and I thought that I can do it in the data.validator.
I also thought, that I can customize visual report to my needs using different UI toolkits.

Proposed Solution

The most flexible way is to have support for custom themes that can be based on different frameworks, etc.

Alternatives Considered

Just add alternative theme based on fluent report.