search: add graphQL schema and stubs for code monitoring

Created by: stefanhengl

This PR adds code-monitors to our GraphQL schema. The goal is to first merge a stub implementation to unlock frontend work.

The schema follows this design. There are still some things missing (events, mutations, mock-store), but I wanted to break it down to limit the size of the PRs.

For the review, I think the most important parts are the changes to the schema.graphql and user.go.

Here is an example of a query that will work:

{
  user(username: "stefan") {
    monitors(first: 1) {
      nodes {
        id
        createdBy {
          username
        }
        createdAt
        description
        owner {
          __typename
          ... on User {
            username
          }
        }
        trigger {
          __typename
          ... on MonitorQuery {
            query
          }
        }
        actions(first: 1) {
          nodes {
            ... on MonitorEmail {
              recipient {
                __typename
                ... on User {
                  username
                }
              }
              priority
              enabled
              header
            }
          }
          totalCount
        }
      }
      totalCount
    }
  }
}

Created by: eseliger

TotalCount is relay spec

Created by: stefanhengl

@rvantonder Juliana reviewed the design. She will most likely implement the frontend part of this. I removed the todos that directly relate to future PRs.

Created by: codecov[bot]

Codecov Report

Merging #15184 into main will decrease coverage by 0.02%. The diff coverage is 14.28%.

@@            Coverage Diff             @@
##             main   #15184      +/-   ##
==========================================
- Coverage   52.71%   52.68%   -0.03%     
==========================================
  Files        1606     1607       +1     
  Lines       80246    80288      +42     
  Branches     7003     7056      +53     
==========================================
+ Hits        42298    42300       +2     
- Misses      34144    34184      +40     
  Partials     3804     3804              

Flag	Coverage Δ
go	52.62% <14.28%> (-0.03%)
integration	30.69% <ø> (-0.11%)
storybook	26.10% <ø> (ø)
typescript	52.83% <ø> (-0.02%)
unit	34.27% <ø> (ø)

Impacted Files	Coverage Δ
cmd/frontend/graphqlbackend/code_monitors.go	0.00% <0.00%> (ø)
cmd/frontend/graphqlbackend/user.go	32.11% <0.00%> (-0.72%)
cmd/frontend/graphqlbackend/graphqlbackend.go	53.46% <100.00%> (+1.16%)
...ient/web/src/search/input/LazyMonacoQueryInput.tsx	77.77% <0.00%> (-22.23%)
client/web/src/repo/RepoContainer.tsx	77.77% <0.00%> (-0.93%)
cmd/repo-updater/repos/types.go	74.20% <0.00%> (-0.25%)