fix: use viewport units for percentage map dimensions (fixes #2186)

[Kakarot35]

Fixes #2186

Problem

folium.Map(height='100%') collapses to nearly zero height when the map
is embedded inside a Django or Flask template. This happens because
height: 100% in CSS requires every ancestor element to have an explicit
height — which page templates typically don't have.

Similarly, folium.Map(height='1000px') can shrink in a non-maximized
browser window because there is no minimum floor set.

Changes

• Viewport units for percentages: when height or width is given as
  a percentage, emit vh/vw instead of %. Viewport units are always
  relative to the browser window size, not the ancestor chain, so they work
  correctly in both standalone and embedded (Django/Flask) contexts.

• Min constraints for pixel sizes: when height or width is given in
  pixels, also emit min-height/min-width so the map cannot shrink below
  its intended size in a smaller window.

• Remove dead CSS rule: the template was emitting
  #map { position:absolute; ... } which never matched anything — folium
  uses hashed IDs like map_d7a447c..., not map. Removed.

Before / After

/* Before — collapses in embedded templates */
#map_abc123 { height: 100%; }

/* After — always fills the viewport correctly */
#map_abc123 { height: 100vh; }

Tests

13 new tests added covering percentage → viewport units, pixel → min
constraints, dead rule removal, and full backwards compatibility.

[Kakarot35]

@hansthen The failing "Publish Docs" check was caused by a missing export in folium/plugins/init.py — now fixed and merged via #2230. This PR should be good to review now. Would appreciate your feedback!

[hansthen]

Not sure why these changes are necessary? Did you branch from an older version of the code? This was changed not too long ago. Using WebDriverWait ensures we wait only until the appropriate conditions are met, instead of waiting a fixed amount of time.

[hansthen]

Apart from the change that removed WebDriverWait, this looks like a great addition. Could you rebase the change on latest master, so we don't have the problem documentation not building?

[Kakarot35]

@hansthen Thanks for the feedback! I see that you are correct, since it was based off of an earlier version, my branch accidentally stripped out WebDriverWait. However, I have rebased back to the current main and put folium/folium.py back into upstream with only the viewport unit updates. The WebDriverWait functionality remains completely intact.

[Kakarot35]

@hansthen I will open another PR for the formatting error in GroupedLayerControl documentation. I think the problem with network timeout to pae-paha.pacioos.hawaii.edu is due to external server connection - please advise whether I should look into that as well.