Classifier: Clean up TaskInput styling

[goplayoutside3]

Package

lib-classifier

Linked Issue and/or Talk Post

Follow-up on #6511. The task input's lost their min-height in that PR, so I've refactored the shared component's styling in this PR.

Describe your changes

• Refactor TaskInput's components with more intuitive CSS
• Remove enzyme and defaultProps where possible

How to Review

• Compare the lib-classifier Storybook on this branch to the deployed Storybook. The Tasks category should look almost identical.
  • The taskInput label and status used to be two different font sizes so I standardized them. Therefore, the drawing tasks and volumetric task in Storybook will look slightly different on this branch.
  • I added stories specifically for different types of TaskInput labels. One that isn't used yet in an FEM project yet is markdown with an image and label. Galaxy Zoo does this and you can preview it on this branch's lib-classifier at https://local.zooniverse.org:8080/?project=5733&env=production

Checklist

PR Creator - Please cater the checklist to fit the review needed for your code changes.
PR Reviewer - Use the checklist during your review. Each point should be checkmarked or discussed before PR approval.

General

• Tests are passing locally and on Github
• Documentation is up to date and changelog has been updated if appropriate
• You can yarn panic && yarn bootstrap or docker-compose up --build and FEM works as expected
• FEM works in all major desktop browsers: Firefox, Chrome, Edge, Safari (Use Browserstack account as needed)

General UX

Example Staging Project: i-fancy-cats

• All pages of a FEM project load: Home Page, Classify Page, and About Pages
• Can submit a classification
• Can sign-in and sign-out
• The component is accessible
  • Can be used with a screen reader BBC guide to VoiceOver
  • Can be used from the keyboard WebAIM guide to keyboard testing
  • It is passing accessibility checks in the storybook

Refactoring

• The PR creator has described the reason for refactoring
• The refactored component(s) continue to work as expected

[goplayoutside3]

This status is always strings of count and label provided by the tool models. No need for markdown.

[goplayoutside3]

Margin and padding are most useful as rigid units like px, not em or rem.

[goplayoutside3]

This Markdownz is needed because the label is controlled by project teams via the lab.

[coveralls]

coverage: 77.39% (+0.03%) from 77.363%
when pulling 2d69e05 on task-input-label
into 57c52de on master.

[kieftrav]

Love the cleanup - LGTM!