Improve setting chip map/format in parameter panel

The solution in #29 for the chip type/map settings works but is not very nice.

Aside from the components needing tidying up, the main issue is how it currently handles the chip map for Oxford type chips and chip format for Custom type chips. The fact that it uses a common constant and state (`chipFormat` and `steChipFormat`) is a problem because it will hold state when switching between one chip type and the other and the user would need to be careful to first clear the map/textfields before resetting it.

This is a bit of an edge case as switching between different chips doesn't usually happen during beamtime BUT it still should be done correctly. A possible solution may just be different states and the `onClick` function for the `Start` button to differentiate between the chip types and maps. This is done in the plan right now.