cmake install targets

[niclar]

@vlevendel et al -please reconsider adding cmake install targets to the library parts of the sdk.

This is needed by our refinitv-rtsdk vcpkg port in the making etc.

[niclar]

This now is implemented in a vcpkg port. I'll link to the PR when I get there

[vlevendel]

@niclar are you using GitHub code found here to build on your platform OR do you used pre-built libraries?

[niclar]

@vlevendel from this source code

[vlevendel]

@niclar Thanks for the clarification and this enhancement request. We will consider it for a future release after appropriate approvals.