Library add apis should process everything before return an error

[yangcao77]

Add apis tend to return on first error, rather than process everything provided.
For example, pass in 5 components, 4 will be added if the 5th is a duplicate but only 1 will be added if the 2nd is a duplicate.

Expected behavior:
add apis should process everything before return. Any valid elements will be added to the devfileObj, and each invalid element will have an error message. the returned error message should be contain all errors