add contributor to coversheet and add plan title to csv export

[pengyin-shan]

A user of DMP Assistant asks us to add contributors to coverage since they are the ones to be more valuable to DMP than creators. This PR achieves this function, also adds 'Title' to csv DMPs.

Changes proposed in this PR:

• Added contributors to coverage of plans. Users will see both roles and contributor names if the role is filled ('Other' is replaced by 'Contributor' as the role name). A role can have many contributors and the same contributor can have more than one role:

• For JSON export, it will show as part of JSON object with the whole contributor information:

"contributor":[{"name":"Wendy Shan Both","mbox":"test@test.com","role":["http://credit.niso.org/contributor-roles//data-curation","http://credit.niso.org/contributor-roles//investigation"],"affiliation":{"name":"University of British Columbia","abbreviation":"UBC","region":null}},{"name":"Wendy Shan","mbox":"test@test.com","role":["http://credit.niso.org/contributor-roles//investigation","other"],"affiliation":{"name":"University of British Columbia","abbreviation":"UBC","region":null}}]

• Added plan title to csv file

[pengyin-shan]

Ready for review

[briri]

This all looks good to me @pengyin-shan