Add a dropdown to select CMIP version

[corviday]

Adds a dropdown to switch between CMIP5 and CMIP6 data. The switch is performed by filtering location data before it is passed to the table.

Demo.

Resolves #71

[corviday]

Feedback from Stephen:

• Time period selector does not appear to do anything
• Could time periods be listed sequentially?
• Could files be sorted by SSP/RCP, then by time period?

[rod-glover]

Coming along nicely! Some comments to do with layout and code style, but no functional changes to suggest.

I'll reply as I can to the feedback items from Stephen.

[rod-glover]

Feedback from Stephen:

• Time period selector does not appear to do anything

It does "do something", but our data is such that it has it nil effect. Okay, confusing.

The selector allows to select for locations that definitely have the specified time period. (As opposed to locations with any time period available, i.e., no filtering. So come to think of it, "Any" would be a much better label than "All".)

Because every location has every time period (it appears), the selector doesn't have any perceptible effect. It may not have much use if this is always true; we should consult with Stephen about that.

• Could time periods be listed sequentially?

What does that mean? If he's talking about the table of files that shows when you click show, you can click on any column header to sort table by that value. That makes it "sequential" in some sense.

• Could files be sorted by SSP/RCP, then by time period?

Yes, click on Time Period column, then on the Scenario Column.

What he might prefer is to have the default sort set up this way. That is easy if it is the requirement. Right now it is either not set at all or is the Type column.

[corviday]

Could time periods be listed sequentially?

What does that mean? If he's talking about the table of files that shows when you click show, you can click on any column header to sort table by that value. That makes it "sequential" in some sense.

I believe Stephen would like the decades in the rows under the "Time Periods" column to be ordered so it's easier to tell at a glance which ones are present. I am going to look into whether this is easy; if not it can be a separate issue.

Could files be sorted by SSP/RCP, then by time period?

Yes, click on Time Period column, then on the Scenario Column.
What he might prefer is to have the default sort set up this way. That is easy if it is the requirement. Right now it is either not set at all or is the Type column.

I'll see if I can set the default to be scenario for the inner files table.

[corviday]

Made suggested code improvements.

Addressed two of Stephen's requests:

• decades appear in order in the "Time Periods" column of the location table
• file table is initially sorted by scenario, then time period

Demo has been updated.

[rod-glover]

Looks great so far.