Draw bonds computed by ASE (#535)

In nglview, if a system is too big bonds will not be computed.
I bypass the "ball+stick" representation defining it as "spacefill" plus shapes that are computed via `ase` connectivity matrix.
It can now draw a large system, tested with plotting ~1000 atoms. The performance is taken care of as well to render the atom plot fast.

---------

Co-authored-by: Carlo <c.pignedoli@gmail.com>
Co-authored-by: Xing Wang <xingwang1991@gmail.com>

.github/workflows/ci.yml

@@ -119,6 +119,9 @@ jobs:
             - name: Check out app
               uses: actions/checkout@v4
 
+            - name: Install povray
+              run: sudo apt-get install povray
+
             - name: Set up Python
               uses: actions/setup-python@v4
               with:

aiidalab_widgets_base/dicts.py

@@ -221,3 +221,21 @@
     "Hs": 1.75,
     "Mt": 1.75,
 }
+
+RGB_COLORS = {
+    "red": (1, 0, 0),
+    "green": (0, 1, 0),
+    "blue": (0, 0, 1),
+    "yellow": (1, 1, 0),
+    "cyan": (0, 1, 1),
+    "magenta": (1, 0, 1),
+    "white": (1, 1, 1),
+    "black": (0, 0, 0),
+    "grey": (0.5, 0.5, 0.5),
+    "purple": (0.5, 0, 0.5),
+    "orange": (1, 0.5, 0),
+    "brown": (0.5, 0.25, 0),
+    "pink": (1, 0.75, 0.8),
+    "lime": (0.75, 1, 0),
+    "olive": (0.5, 0.5, 0),
+}