Reflect layer updates on the hierarchy map

[anayaml]

One of the limitations of Geonode's default implementation is that updates made to a layer after the layer in question are added to a map does not reflect on the map.

For example, the user creates a map called 01Map, and adds a layer named layer_01, and saves the map. However, it then updates the name of layer_01 for Layer 01.

The layer name is updated in the layer table, however, if the user will access the 01Map that he created before, the now named Layer 01 will still be named layer_01 in the map layer list.

It seems that the map stores other data in addition to the layer ID in the database, causing the non-replication of the update made by the user.

A possible solution would be to update the migration that generates the map table in geonode, and make it save only the ID. And when loading the map, search for the IDs in the layer table and return the most recent data.