Add aws_key_pair resource

[vaspahomov]

Signed-off-by: vaspahomov vas2142553@gmail.com

Description of your changes

Added aws_key_pair resource

I have:

• [x] Read and followed Crossplane's contribution process.
• [x] Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

Manually tested in my AWS account

[haarchri]

thanks for Implementation can you add working example ?