Fix wordle logic

[danshea00]

The current logic in wordle_server.c is incorrect. If a misplaced letter keeps appearing more than the number of times it has appeared in the target word, it should not keep showing as yellow.

Example 1:

word:     hello
guess:    eeeee
output:   YGYYY
correct:  XGXXX

Example 2:

word:     hello
guess:    lelel
output:   YGGYY
correct:  YGGXX

Where Y is yellow, G is green, and X is grey.

Concerns are:

• It might be confusing to have to call the calculate_states function then pack MRs using the states global
• Not sure if static alphabet sized array and lines like counts[word[i] - 'a']++ is clear enough

[Ivan-Velickovic]

This is the first non-trivial change to the code since the release of the tutorial, which means it's a good test for the CI that I will setup soon. So I'll leave this PR open until that's done.