Add forecast_event and depth_class model

[lucernae]

Used for forecast date filters

[lucernae]

Update:

• [X] Create model for forecast_event to browse flood forecast
• [X] Refactor browse flood interaction to use forecast_event model and switch to flood_event table instead of flood draw table
• [X] Make GeoServer Layer from SQL view to filter/show flood forecast. Layer name: 'kartoza:flood_forecast_layer'
• [X] Add WMS layer of flood, filtered using CQL for corresponding forecast_event_id/flood_event.id from geoserverUrl + 'kartoza:flood_forecast_layer'
• [X] Export QML style to SLD to use in the WMS style of flood forecast. QML Source: https://github.com/kartoza/fbf-project/blob/develop/Datasets/Flood/flood_classes/flood_classes.qml
• [X] Query available forecast information from database
• [X] Make SQL function called flood_event_forecast_list_f to show available forecast based on lead time
• [X] Make SQL view to aggregate flood extent (to be used as bbox zoom in front end). View is called flood_event_extent_v
• [X] Zoom to flood forecast if forecast is selected
• [X] Uploading flood forecast will zoom and display the flood

Not done (will let @ann26 integrate it in different PR):

• What happens if there are more than one forecasts in a day? What is the interaction now?
• Selecting/Zooming flood forecast should trigger dashboard refresh
• Trigger status needs to be communicated in calendar browser and dashboard.
• Flood browser calendar doesn't show up in Firefox and Safari. Showed up in Chrome and Opera.

[lucernae]

Screenshots:

• Browsing flood:

• Uploading flood then zoom

[lucernae]

fix #88

[lucernae]

fix #53

[lucernae]

I will merge this @ann26 You will have some conflicts later on because the flood browse logic gets significant overhaul.