Popup: respect `popupMaxFeatures` parameter

[nboisteault]

Fix #4517

Funded by 3Liz

[3liz-bot]

The backport to release_3_7 failed:

The process '/usr/bin/git' failed with exit code 1

stderr

``` error: could not apply 330becdf5... Popup: respect `popupMaxFeatures` parameter hint: After resolving the conflicts, mark them with hint: "git add/rm ", then run hint: "git cherry-pick --continue". hint: You can instead skip this commit with "git cherry-pick --skip". hint: To abort and get back to the state before "git cherry-pick", hint: run "git cherry-pick --abort". hint: Disable this message with "git config advice.mergeConflict false" ```

stdout

``` Auto-merging assets/src/modules/Popup.js CONFLICT (content): Merge conflict in assets/src/modules/Popup.js Auto-merging tests/end2end/playwright/popup.spec.js Auto-merging tests/qgis-projects/tests/popup.qgs CONFLICT (content): Merge conflict in tests/qgis-projects/tests/popup.qgs Auto-merging tests/qgis-projects/tests/popup.qgs.cfg CONFLICT (content): Merge conflict in tests/qgis-projects/tests/popup.qgs.cfg ```

To backport manually, run these commands in your terminal:

# Fetch latest updates from GitHub
git fetch
# Create a new working tree
git worktree add .worktrees/backport-release_3_7 release_3_7
# Navigate to the new working tree
cd .worktrees/backport-release_3_7
# Create a new branch
git switch --create backport-4537-to-release_3_7
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick 330becdf5d7c513445df91f31bbc2f78dde0fc49
# Push it to GitHub
git push --set-upstream origin backport-4537-to-release_3_7
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release_3_7

Then, create a pull request where the base branch is release_3_7 and the compare/head branch is backport-4537-to-release_3_7.