New checker for when an index-lookup is used together with dict.items()

[yushao2]

Is your feature request related to a problem? Please describe

As discussed with @cdce8p in #4445 :

A checker can be implemented to detect for instances where an index-lookup is used with dict.items()

for k10, v in b_dict.items():
  val = v + 2
  print(b_dict[k10])  # this is bad

Describe the solution you'd like

A new checker should be implemented to discourage use of index-lookup when the value can be pulled from v

for k10, v in b_dict.items():
  val = v + 2
  print(b_dict[k10])  # [use-value-from-dict-items]

Additional context

We could also think about what should happen if an index-lookup is used together with dict.items.

for k10, v in b_dict.items():
    val = v + 2
    print(b_dict[k10])

--
I realize this might all be a bit much at once, but keep in mind: The work you have already done is really good! Especially for a first-time contributor These are now just the finishing touches. If you encounter any issues or need help, please don't hesitate to ask.

@cdce8p,

I think this should be in a different error message altogether -- should I try my hand at implementing it within this PR or perhaps I should create a separate PR for that. I think it might be better to not bloat up this PR

Originally posted by @yushao2 in #4445 (comment)

[yushao2]

@cdce8p please assign this to me, i'll work on this alongside str-partition checker