refactor: rename roller to prover

[0xmountaintop]

Purpose or design rationale of this PR

Describe your change. Make sure to answer these three questions: What does this PR do? Why does it do it? How does it do it?

PR title

Your PR title must follow conventional commits (as we are doing squash merge for each PR), so it must start with one of the following types:

• build: Changes that affect the build system or external dependencies (example scopes: yarn, eslint, typescript)
• ci: Changes to our CI configuration files and scripts (example scopes: vercel, github, cypress)
• docs: Documentation-only changes
• feat: A new feature
• fix: A bug fix
• perf: A code change that improves performance
• refactor: A code change that doesn't fix a bug, or add a feature, or improves performance
• style: Changes that do not affect the meaning of the code (white-space, formatting, missing semi-colons, etc)
• test: Adding missing tests or correcting existing tests

Deployment tag versioning

Has tag in common/version.go been updated?

• No, this PR doesn't involve a new deployment, git tag, docker image tag
• Yes

Breaking change label

Does this PR have the breaking-change label?

• No, this PR is not a breaking change
• Yes

---

• To see the specific tasks where the Asana app for GitHub is being used, see below:
  • https://app.asana.com/0/0/1205098500361486

[github-actions]

LCOV of commit 5388cca during Contracts #1218

Summary coverage rate:
  lines......: 52.0% (884 of 1701 lines)
  functions..: 69.7% (200 of 287 functions)
  branches...: no data found

Files changed coverage rate: n/a