Create prototype heatmap visualization.

[BinarySoftware]

Pull Request Description

This is a prototype, will appear on the movie for the website, so it's code should appear in this repo too.

It is based on d3.js. Example:

    quotient1 = Enso_project.data / "data.csv"
    operator2 = quotient1.read_csv

It works on our Table type, so just select operator2 and show Heatmap on it :)

Important Notes

Checklist

Please include the following checklist in your PR:

• The CHANGELOG.md was updated with the changes introduced in this PR.
• The documentation has been updated if necessary.
• All code conforms to the Rust style guide.
• All code has automatic tests where possible.
• All code has been profiled where possible.
• All code has been manually tested in the IDE.
• All code has been manually tested in the "debug/interface" scene.
• All code has been manually tested by the PR owner against our test scenarios.
• All code has been manually tested by at least one reviewer against our test scenarios.

[wdanilo]

Also, please be sure this wors for table - make an example with table, and lets merge it! <3