Rename `PaaS` category to `Infrastructure Management`

Rename the "PaaS" category to Infrastructure Management. Relevant discussion here https://gitlab.com/gitlab-org/gitlab-ce/issues/63151.

Summary

Product initially had intent to rename the PaaS category to either Application Development Platform or DevOps Platform. In conversation between product and marketing (meeting notes), marketing expressed intent to use the verbiage "platform" to describe GitLab (ie. GitLab = DevOps platform delivered as a single application). In conclusion, marketing will work to build on the "DevOps platform" messaging at a top level, PMM will publish "PaaS-like" use-cases, and product will rename PaaS to Infrastructure Management.

/cc @twbarr @markpundsack @sfwgitlab @williamchia

Approvals

• CEO - @sytses
• VP of Product - @sfwgitlab
• VP of Product Strategy - @markpundsack
• Director of Product - @kencjohnston
• Director of Engineering - @dhavens

Informed

• Senior Director of Development - @clefelhocz1
• Director of Quality - @meks
• VP of Engineering - @edjdev