Improving various tests with parametrize

[nmcguire101]

#2522 Adding more improvements to tests

Description:
Improved test tests\ignite\contrib\metrics\test_accuracy.py using pytest parametrize

Check list:

• New tests are added (if a new feature is added)
• New doc strings: description and/or example code are in RST format
• Documentation is updated (if required)

[vfdev-5]

@nmcguire101 thanks for the PR. By the way, for effectively contributing using git, please check https://github.com/firstcontributions/first-contributions
Basically, the idea is to create new branch synced with remote master for every new feature. This would help to avoid keeping previous unrelated commits.

[vfdev-5]

@nmcguire101 can you please also update test_multiclass_input

[vfdev-5]

LGTM, thanks @nmcguire101