Create "Copy view" item in view menu

[cmdcolin]

Adds a new button to copy a view into a new view panel based on the state of an existing view. Similar to copying track

There is a thing where internal state id's could collide between these two views which is tricky, but my initial testing found that it kinda worked

[cmdcolin]

looks like there are some weird things like clicking a feature ends up causing trouble because the feature widget uses a reference to view, and then it produces an error that it can't resolve ID unambiguously

screenshot after clicking feature in breakpoint split view:

[cmdcolin]

to fix, we probably need a principled way to strip or reassign new id's to the copied view. there are some sprinkled examples that are a little hacky that strip the IDs from snapshot objects, which are automatically regenerated on model import

e.g.

jbrowse-components/packages/sv-core/src/util.ts

Lines 54 to 59 in e064f94

	export function stripIds(arr: Track[]) {
	return arr.map(({ id, displays, ...rest }) => ({
	...rest,
	displays: displays.map(({ id, ...rest }) => rest),
	}))
	}