maps: conditionally display map & warning messages

[codemacabre]

Summary

• Pass variables any_nodes_with_geometry and any_spans_with_geometry to template
• Conditionally show/hide map based on data validity
• Conditional messages based on data validity
• Conditionally colour 'Visualisation' section header based on data validity

#6

Verify

1. Upload valid JSON

   • 'Visualisation' section header will be success green and map should display
     

2. Upload JSON without valid geometry

   • 'Visualisation' section header will be warning yellow, along with appropriate message, and map will not display
     

3. Upload invalid JSON

   • 'Visualisation' section header will be danger red, along with appropriate message, and map will not display
     

[Lathrisk]

This looks good to me. The linting changes are quite extensive, but also pass our automated linting checks in the repo. I guess we don't want to regularly change code styles if we use different auto-linters, but otherwise looks good. Any thoughts, @odscjames?

[odscjames]

We don't have auto-linters for HTML and I don't want to get into that now - ideally PR's would have minimal changes. This allows other PR's to be merged in and preserves the history. Can the 3 commits in this PR be squashed?

Also, noting the messages in the template don't match the 3 in #6 (comment) . It's not possible to fully do the red message now, as the {{error details}} template variable isn't available but we could match it as much as possible. That could be in this PR or a new PR after tho.