Look into removing the serialization traits on `AppState`

[IsseW]

Currently AppState has a serialization derive where most of the fields skip serialization. The only fields actually using it now are RedapServers and AppOptions.

Ideally the parsing for these two would be done separately, and getting to remove all of the serde(skip) and unnecessary serde derives on TimePanel and SelectionPanel.

Another benefit we could get if we split these up is that if any parsing becomes invalid it doesn't have to reset everything.