Make Commit After Design Space Operation with Same Input and Output Optional

[nroehner]

Add a Boolean argument "isCommit" to the JoinDesignSpace, orDesignSpaces, repeatDesignSpaces, andDesignSpaces, and mergeDesignSpaces methods in DesignSpaceService with a default value of true.

If "isCommit" is true, then a merge commit should be created by calling the mergeVersionHistories method as normal. If "isCommit" is false and the arguments of the operator are such that the output design space is also one of the input design spaces, then no merge commit should be created (do not call mergeVersionHistories).