Add sliders in test case edit.

src/lib/calculations.ts

src/lib/components/WaterfallView.svelte

src/lib/components/latchkeys/Latchkey.svelte

src/lib/components/test_cases/TestCaseEdit.svelte

src/lib/components/test_cases/TestCaseView.svelte

src/lib/components/test_cases/TestCasesPane.svelte

src/lib/components/variables/FormulaView.svelte

src/lib/components/variables/VariableInput.svelte

...omponents/variables/VariableReferredScaleParameter.svelte

...omponents/variables/VariableReferredValueParameter.svelte

src/lib/components/variables/VariableView.svelte

src/lib/components/waterfalls/Waterfall.svelte

src/lib/decompositions.ts

src/lib/situations.ts

src/lib/variables.ts

src/lib/websockets.ts

src/routes/__layout.svelte

src/routes/index.svelte

src/routes/simulations/[simulation].svelte