Missing platform numbers for single platform stations

[ben-fletcher]

Describe the bug
Missing platform numbers for single platform stations

To Reproduce
Steps to reproduce the behavior:

1. Go to the singleboard view for Warwick(WRW)
2. You should see no platform details

Expected behaviour
Warwick only has one platform, so it should be smart and set the platform number to be '1'.

To get this information globally, it should use the existing station lookup used for the search to also cache how many platforms the station has. If the station has one platform and the data provided has no platform then we should set the platform to 1