Prevent and hide collapse/expand in Dynamic SVG parameters table in layer symbology

[jgrocha]

Description

Fix #42183

This prevents the tree column to be expanded/collapsed. That was causing the crash.

I've hidden also the small triangle decoration.

Proposal:

Before:

[github-actions]

The backport to release-3_16 failed:

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

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_16 release-3_16
# Navigate to the new working tree
cd .worktrees/backport-release-3_16
# Create a new branch
git switch --create backport-42185-to-release-3_16
# Cherry-pick the merged commit of this pull request and resolve the conflicts
git cherry-pick --mainline 1 08f85619b1af77091c5b43f9c18989c015a6dc66
# Push it to GitHub
git push --set-upstream origin backport-42185-to-release-3_16
# Go back to the original working tree
cd ../..
# Delete the working tree
git worktree remove .worktrees/backport-release-3_16

Then, create a pull request where the base branch is release-3_16 and the compare/head branch is backport-42185-to-release-3_16.