Merge tcpinfo v2 parser & update dependencies

[stephen-soltesz]

• [x] merge parser, gardener, and prometheus changes for tcpinfo v2
• [x] verify that tcpinfo parser is working in staging
• [x] deploy to production
• [ ] update website documentation
• [ ] update unified views

[stephen-soltesz]

Deleting v1 portions tracked in https://github.com/m-lab/etl/issues/1074

[stephen-soltesz]

Remaining documentation steps are now part of https://github.com/m-lab/etl/issues/1076