[feature] .items() for Maps

[RiedleroD]

a method to get (key, value) pairs from a Map, e.g.:

input: {1: 2, 2: 4, 3: 6}

output: [[1, 2], [2, 4], [3, 6]]

this would be useful for iterating over maps, e.g. when correlating with another map:

# both of these have album ID as their key
albumart = {…}
albumtitles = {…}
for id, title in albumtitles.items():
    art = albumart[id]
    pass # do stuff with title and art

some notes:

• the pairs should be final and immutable.
• I'm assuming there's no unpacking support for for loops yet? would also be very beneficial.

[mcquenji]

unpacking is not supported yet as record types (or tuples in other languages) have yet to be implemented