Add a method for subvector retrieval in `im::Vector` following the example of `subvec` (https://clojuredocs.org/clojure.core/subvec) from Clojure

[svblsvljb]

Currently, there is no way to retrieve a subvector of a Vector by specifying a range. While vector.clone().slice(/* ... */) provides similar functionality, it does not panic on out-of-bounds indices and do unnecessary (for our use case) append operation (https://docs.rs/im/latest/src/im/vector/mod.rs.html#1345).

I suggest adding a separate method to the Vector implementation that allows users to specify a range and returns a new Vector with the elements in the specified range.