CMake installation location is unusual

### Security issue notifications

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### Problem:

The installation of the .cmake files is unusual (not for example the same as the [aws-sdk-cpp](https://github.com/aws/aws-sdk-cpp/blob/4bccd6b30b6c8b1b995aa166a10f5a937c620e1f/cmake/utilities.cmake#L135) ); it's more common to install the cmake config to lib/cmake/project/project-config.cmake and in this way it's easy to pick up and use in dependent projects. Changing this location I can see this being an issue to people who've already worked around this so you may well **not** want to do this but i bring it up as it would make my life easier.

### Solution:

Change the installation directory (or maybe even do both for a while for backward compatibility) in InstallLogic.cmake from ` ${AWS_INSTALL_TARGET}/cmake ` to ` cmake/${AWS_INSTALL_TARGET} `

### Out of scope:

Nothing

[//]: # (NOTE: If you believe this might be a security issue, please email aws-security@amazon.com instead of creating a GitHub issue. For more details, see the AWS Vulnerability Reporting Guide: https://aws.amazon.com/security/vulnerability-reporting/ )

Start by reading InstallLogic.cmake and locate the installation rule that uses ${AWS_INSTALL_TARGET}/cmake. Compare it with the requested cmake/${AWS_INSTALL_TARGET} layout and verify the resulting CMake package path; done means dependent projects can find the configuration, with any backward-compatibility choice documented.

Written by the indexing model from the issue text.