Add tabs for Analyze Related Bills section

[smplater]

** On the top layer, the tabs should filter the related bills search by relation. There should be tabs for "Virtually Identical," "Related," and "Prior Enacted"

** On the bottom layer, the tabs should filter the related bills search by Congress. There should be tabs for "Current Congress" and "Prior Congress"

[aih]

Questions:

1. I understood one of the main values for the related bills is to identify bills across congresses. I'd think the first of the 'bottom' tab would be 'All' (including this and prior congresses) and the second tab would be 'Current Congress'. I'm not sure what 'Prior Congress' would mean-- for a current bill, I don't think it's meaningful to show only related bills from prior congresses.

2. The tab-within-a-tab design seems cluttered and not very clear. Do we really want this? The 'relation' (identical, prior-enacted, etc) is in a column of the current data. This can currently be filtered with the tab's search:
   

or by sorting the 'Reason' column:

We can, similarly, add a column-level drop-down filter to select only the 'procedurally-related' bills.

[smplater]

1. We want to show "Current Congress" to show users separate data for the Current Congress (116th 2019-2020). We want to show "Prior Congress" to show data for all previous Congresses that came before the 116th, but that don't include the 116th.
2. We originally chose the tab view because we wanted to show the users the different ways bills can be related while separating their view of the data. If possible, please add tab view back.

[nkinaba]

Issue closed due to change in UI requirements for the tabs.
Virtually identical, related, and prior enacted tabs are no longer part of the UI requirement.
The data for the relationship of the related bills will be displayed in a column.

See issue #217 for updated requirements