Change "Control Vocabulary" to "Controlled Vocabulary"

[mauzey1]

As mentioned in PCMDI/cmor3_documentation#55, the documentation has used the term "Controlled Vocabulary" rather than "Control Vocabulary". We should change mentions of "Control Vocabulary" to "Controlled Vocabulary" in CMOR to reflect the documentation. This includes changing the parameter name of the CMIP6_CV.json path from _control_vocabulary_file to _controlled_vocabulary_file.

[taylor13]

sounds good to me, but not particularly urgent.