wip: added manual dataset creation

[boandriy]

added manual dataset creation UI

[chriswhong]

I pushed a commit with some major refactoring:

• Splits DatasetHeader into two components: DatasetHeader, which contains all of the selectors and actions used when rendering the Header for the active dataset and DatasetHeaderRender which is a simplified rendering component.
• DatasetHeaderRender has some improvements to the dataset name and title. Now they are always text inputs that change their styles when editable/focused. This prevents the shift we were seeing when editing these values. Also added styles to make them match the mockups/color scheme.
• DatasetHeaderRender is then used by ManualDatasetCreation to allow for editing of the name and title.

When the user selects a file to upload:

• we take the filename and use it to replace both the dataset name and title, but only if they have not been changed from the default values. If the user has already changed one of these fields, it will not be changed when the file is added.
• we also update the commit title to include the file name, which is a nice way to add some traceability

Note For now I have removed the ability to edit a dataset's title from the header on a dataset the user owns. I have kept all of the UI and logic for this in DatasetNameCommitModal which is unused, but we can bring this back if we need it. I think what we will probably want here is to just bring the user to the dataset editor UI if they want to edit the meta.title.

[chriswhong]

To get this PR across the finish line:

• [ ] Add the "close" (X) IconButton as a child of DatasetHeaderRender to allow the user to cancel creating a new dataset. This should just navigate to the previous route (it's essentially a back button)
• [ ] Add the modal that appears on commit. See the video posted by Tefy in #product.
  • This modal should appear when the user clicks commit
  • This modal should not have any input fields in it, as we have already updated the name and title based on the filename
  • This modal should show confetti once the request comes back successful and the dataset has been created.
  • The final screen should say "Dataset Created" and give the user two buttons: "Add Metadata" and "Show Dataset Preview"