[WIP] Execute mypy on opentelemetry-sdk/src

[prabhakarjuzgar]

Description

Run mypy on opentelemetry-sdk/src

Fixes # 773

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• tox -e mypy

Does This PR Require a Contrib Repo Change?

• Yes. - Link to PR:
• No.

Checklist:

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added
• Documentation has been updated

[linux-foundation-easycla]

• ✅login: prabhakarjuzgar / (17d43aa)
• ✅login: prabhakarjuzgar / (17d43aa, 5ff457d)
• ✅login: prabhakarjuzgar / (17d43aa, 5ff457d, 53f536e)
• ❌ The commit (5c76d9d, b2fe404, e99e464). This user is authorized, but they must confirm their affiliation with their company. Start the authorization process by clicking here, click "Corporate", select the appropriate company from the list, then confirm your affiliation on the page that appears. For further assistance with EasyCLA, please submit a support request ticket.

[emdneto]

I think at this moment would be more interesting if we really start adding type hints accordingly. So, if you are still open to work on this, something like this #4053 would be very appreciate. You can also start with small fixes (i.e., single folder at max 2) which will make reviews easier. Finally, to contribute to this project you should sign CLA, please.

[prabhakarjuzgar]

Ok, I will make changes in 1 or 2 files at a time in a PR. I am not sure if there is a way to reject this PR as I do not have permission to do so.