Frontend: Add small inline quick 'Add Forecast' form at the top of the forecast table

[omarkohl]

e.g. for adding binary forecasts without a description in a fast way.

[omarkohl]

Could be inline above the table of forecasts.

• Fields: Title, "Yes" probability, Reason, Resolution.
• Resolution could default to midnight.
• Small +24h button next to Resolution field.
• Only for binary forecasts, defaulting to Yes/No (with other languages in the future default to that language). Only specify the Yes probability and calculate No.
• Leave the resolution the same after adding to allow creating multiple forecasts.
• Use the "tab" key to navigate and Ctrl+Enter to create the forecast, then jumping back to the first field for adding the next forecast.
• Resolution should be last because it's the least likely to change when adding multiple forecasts.