Remove duplicate code from `richworld` namespace

[ForNeVeR]

See this:

Hyperspace/src/hyperspace/client/richworld.clj

Lines 39 to 48 in 91d0b6b

	;; FIXME: Duplicate code
	new-missiles (->> missiles
	(filter #(circle-X-rectangle? % world))
	(remove #(circle-X-any-circle % planets))
	(map #(simulation/update-particle % planets simulation/simulation-step)))
	new-fragments (->> fragments
	(concat broken-particles)
	(filter #(circle-X-rectangle? % world))
	(remove #(circle-X-any-circle % planets))
	(map #(simulation/update-particle % planets simulation/simulation-step)))