add captions to map panels; adjust map layout to better fit titles and captions

[RyanCoulsonCA]

Related Item(s)

#503

Changes

• Added the caption property to map panels. When provided, the caption will appear under the map as it does for images and slideshows.
• Adjusted the structure of the map panel:
  • Instead of hardcoding the map height based on whether there's a horizontal or vertical ToC, and based on whether there's a title or not, the height of the entire panel is now simply based on the ToC orientation.
  • Within the panel, the title and caption will take up as much space as required and the map will simply fill in the rest of the available space.
• Point of interest titles now support HTML
• Removed self-start property from slideshow children. Elements should now appear in the center of the slideshow component.

Testing

Steps:

1. Open the demo page.
2. I've added a new slideshow containing 4 maps with different scenarios (just under the interactive map panel, the text panel accompanying it is titled RAMP4 Test). Ensure that these are rendering correctly on desktop and mobile.

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This change is 

[github-actions]

Your demo site is ready! 🚀 Visit it here: https://ramp4-pcar4.github.io/story-ramp/fix-503/#/en/00000000-0000-0000-0000-000000000000

[yileifeng]

Reviewed 6 of 6 files at r1, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @RyanCoulsonCA)

[RyanCoulsonCA]

Added an extra fix to this PR for https://github.com/ramp4-pcar4/tcei-tmx-cwa-storylines/issues/96:

• Point of interest titles now support HTML

[yileifeng]

Reviewed 1 of 1 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @RyanCoulsonCA)

[RyanCoulsonCA]

Aaaand one more addition:

• Removed self-start property from slideshow children. Elements should now appear in the center of the slideshow component:

Before:

After:

[yileifeng]

Reviewed 1 of 1 files at r3, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @RyanCoulsonCA)

[IshavSohal]

Reviewed 5 of 6 files at r1, 1 of 1 files at r2, 1 of 1 files at r3, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @RyanCoulsonCA)

[yileifeng]

Reviewed 4 of 4 files at r4, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @RyanCoulsonCA)