In FunctionSelector.svelte allow a faster way to select functions.

Ideas:

• allow starring functions. Starred functions show at the top. We store the info in metadata as starred_functions
• allow assigning Alt - 1 ... Alt - 9 quick access shortcuts, like for notes except it would only work when in function selection dialog when filter is empty
• allow selecting first 10 functions with Ctrl + 0 ... Ctrl + 9. Especially useful in combination with starring