Downgrade RSSDK2 warning message to status

[shrijitsingh99]

Resolves #3490
I just suppressed the warning and display a message for now.
Anything else expected or any changes required?

[kunaltyagi]

The linked issue contains CMake log such as:

-- Could NOT find RSSDK (missing: RSSDK_LIBRARIES RSSDK_INCLUDE_DIRS) 
-- RealSense SDK support: not building because RSSDK not found

It'd be better if the RSSDK2 log were similar to RSSDK.

[SergioRAgostinho]

Preferably yes, but I also recon that in RSSDK we search for the files and directories ourselves, while in RSSDK2 we're using and looking for their config file (correct me if I'm wrong). Either it finds everything or it doesn't. So it might not be worth to aim for this level of uniformed report because the find mechanisms are not exactly the same.

[kunaltyagi]

But the messaging mechanism is written by us. Just the message(STATUS...) bit needs changing. Output is already limited using the QUIET flag

[SergioRAgostinho]

Let me clarify then. Having this is ok

-- Could NOT find RSSDK2 

But I wouldn't care about having this

-- Could NOT find RSSDK2 (missing: whatever reasons.) 

[shrijitsingh99]

But the messaging mechanism is written by us. Just the message(STATUS...) bit needs changing. The output is already limited using the QUIET flag

As I understood, I updated the status message to be in line with other CMake logs

I didn't use "find_package_handle_standard_args(RSSDK2 DEFAULT_MSG RSSDK2_LIBRARIES RSSDK2_INCLUDE_DIRS)", since as already mentioned it would be redundant to display what's missing in this case.