groupby() with arbitrary Series in by list raises an error

[itamarst]

This is a follow-up on #1770, for the more complex case where the Series is not just an untouched Series from the DataFrame.

import pandas as pd
import modin.pandas as mpd

data = {
    "a": [1, 1, 2],
    "b": [11, 11, 22],
    "c": [111, 111, 222]
}

df = pd.DataFrame(data)
df = pd.concat([df])
ref = df.groupby(["a", "b", df["c"] + 1]).size()
print(ref)

df = mpd.DataFrame(data)
df = mpd.concat([df])
exp = df.groupby(["a", "b", df["c"] + 1]).size()
print(exp)

(The specific error raised will be different once #1842 is merged, but it errors out both before and after that PR.)

Originally reported by @ienkovich.

[itamarst]

Will see if I can figure out this one too.

[itamarst]

I've gotten size() working, but... it seems like there's more broad need for code, e.g. __iter__ breaks. So will move on to that and see what else is broken too.