Update metadata for time series plots

The titles, link texts, and svg names for 2 figures on the SalishSeaCast page
have been updated. The entities represented in the figures have been changed -
from Mesodinium rubrum to Diatoms, and from Mesozooplankton and Microzooplankton
to Z1 and Z2 - to reflect changes in the output fields from the V21-11 model.

salishsea_site/views/salishseacast.py

@@ -333,14 +333,14 @@
             svg_name="nitrate_diatoms_timeseries",
         ),
         FigureMetadata(
-            title="Mesodinium rubrum and Flagellates Concentrations",
-            link_text="Surface Mesodinium rubrum and Flagellates Concentrations",
-            svg_name="mesodinium_flagellates_timeseries",
+            title="Diatoms and Flagellates Concentrations",
+            link_text="Surface Diatoms and Flagellates Concentrations",
+            svg_name="diatoms_flagellates_timeseries",
         ),
         FigureMetadata(
-            title="Mesozooplankton and Microzooplankton Concentrations",
-            link_text="Surface Mesozooplankton and Microzooplankton Concentrations",
-            svg_name="mesozoo_microzoo_timeseries",
+            title="Z1 and Z2 and Zooplankton Concentrations",
+            link_text="Surface Z1 and Z2 and Zooplankton Concentrations",
+            svg_name="z1_z2_zooplankton_timeseries",
         ),
     ],
 )