Weather Symbol

### What problem does your feature request solve?

It would be useful to be able to determine how likely the weather symbol will change based on different ensemble members and model configurations to really understand what the public is likely to see.

### Describe the solution you'd like

This should use the existing weather symbol code that exists in other parts of the Met Office. This should live in `Daily Weather`.

For further details (including about reviewers) please refer to #1550.

Start with the related issue #1550 and the existing weather symbol code referenced there, then inspect the Daily Weather area. Done means users can determine how likely the weather symbol is to change across ensemble members and model configurations.

Written by the indexing model from the issue text.