campaigns: Improve UX of using the src CLI with Automation

Created by: mrnugget

This is a meta-issue to collect the issues in the src-cli repository that I plan to be working on in the next iteration:

• a8n: Node package upgrade campaign not failing when yarn-error.log file produced https://github.com/sourcegraph/src-cli/issues/131
• search and scopeQuery return different number of results https://github.com/sourcegraph/src-cli/issues/125
• a8n: Need command to either run automation ignoring the cache and/or deleting the cache https://github.com/sourcegraph/src-cli/issues/115
• a8n: Cannot use count in scopeQuery https://github.com/sourcegraph/src-cli/issues/114
• a8n: Doesn't support namespaced Docker image names e.g, sourcegraph/rxjs-upgrade https://github.com/sourcegraph/src-cli/issues/113
• a8n: Steps should not be cached if the Docker image has been rebuilt. SHA needs to be checked, not just the tag https://github.com/sourcegraph/src-cli/issues/112
• Diff produced by src actions exec doesn't respect gitignore https://github.com/sourcegraph/src-cli/issues/137
• Don't fail actions exec if only a subset of repositories failed https://github.com/sourcegraph/src-cli/issues/129
• a8n: Output shows duplicate lines when verbose flag is given https://github.com/sourcegraph/src-cli/issues/119
• Unzip failed with interactive message https://github.com/sourcegraph/src-cli/issues/109
• a8n: Hitting Ctrl-C when running src action exec doesn't kill spawned containers https://github.com/sourcegraph/src-cli/issues/117
• Add src actions create command to create actions.json boilerplate https://github.com/sourcegraph/src-cli/issues/153
• Use JSON schema to validate that a given action definition is valid https://github.com/sourcegraph/src-cli/issues/155