Feature/update project model

[maxceem]

• feat: update "project.terms" type to string Update type of the field "terms" in Project model to array of strings #614
• feat: add "project.groups" field Add field "groups" in Project model #616

Steps to Deploy

1. Merge PR for project ES processor Feature/update project model project-processor-es#53
2. Merge this PR
3. Run 2 SQL migration scripts for DB:
   • https://github.com/topcoder-platform/tc-project-service/compare/feature/update-project-model?expand=1#diff-eea1790b5da98adb21c4b92a13b5b11bf747dd775dbe785a75852eb24fa6df52
   • https://github.com/topcoder-platform/tc-project-service/compare/feature/update-project-model?expand=1#diff-19722eab652dca0009f0f75e6fc646cd12ffc8929b47e9567d70d06dbe795ceb
4. Reindex data in ES:
   • remove ES index projects as mapping has been updated
   • create ES index projects
   • re-index all the projects

[vikasrohit]

@maxceem I am getting. following warning when running SQL https://github.com/topcoder-platform/tc-project-service/compare/feature/update-project-model?expand=1

NOTICE:  word is too long to be indexed
DETAIL:  Words longer than 2047 characters are ignored.
NOTICE:  word is too long to be indexed
DETAIL:  Words longer than 2047 characters are ignored.

Same warnings are returned with second migration script as well.