Return metadata for MCOS objects instead of throwing error if read is unsuccessful

[foreverallama]

Added a try-catch block for load_subsys!() and load_mcos_object(). Any errors caught will log a warning and return raw metadata instead. This could work as a fix towards #219

Added test cases for both v7 and v7.3 formats:

• corrupted_subsystem.mat contains an unsupported FileWrapper version (v5) which should throw an error.
• corrupted_mcos_object_metadata.mat contains an object ID that does not exist in subsystem which should lead to a BoundsError.

It would be a good idea to test for the specific warning message but I couldn't figure out how to do that with @test_logs

[matthijscox]

Second argument in the test logs tuple should be the message:

julia> @test_logs (:warn,) begin @warn "boo" end

julia> @test_logs (:warn,"boo") begin @warn "boo" end

julia> @test_logs (:warn,"moo") begin @warn "boo" end
Log Test Failed at REPL[7]:1

[foreverallama]

I think that looks for an exact match? I'm logging the actual error as well with the warning message. Should I paste the whole error message or can I look for a partial match instead?

[matthijscox]

I normally indeed just match the whole warning message... never tried to insert a regex. Should work according to docstring of @test_logs: "Regexs in the pattern will match string or Symbol fields using occursin."

Seems so:

julia> @test_logs (:warn,r"^bo") begin @warn "boo" end

julia> @test_logs (:warn,r"^mo") begin @warn "boo" end
Log Test Failed at REPL[11]:1

[foreverallama]

The regex worked, thanks!

[matthijscox]

okay, looks good, merging