Add GraphQL mutation `projectBlobsRemove`

What does this MR do and why?

Add GraphQL mutation projectBlobsRemove

Allows maintainers+ to replace text via the GraphQL API.

Takes 2 arguments:

projectPath - full path of the project to redact blobOids - list of blob object ids

Returns nothing when successful Returns errors when something went wrong

Part of https://gitlab.com/gitlab-org/gitlab/-/issues/450701

Changelog: added

MR acceptance checklist

Please evaluate this MR against the MR acceptance checklist. It helps you analyze changes to reduce risks in quality, performance, reliability, security, and maintainability.

How to set up and validate locally

Install git-filter-repo locally (not bundled with GDK yet)

brew install git-filter-repo

Run mutation

mutation {
  projectBlobsRemove(input: { projectPath: "Flightjs/flight", blobOids: ["53855584db773c3df5b5f61f72974cb298822fbb"]}) {
    errors
  }
}

Details on how to find blobs are documented here https://gitlab.com/gitlab-org/gitlab/-/issues/450701#note_1840815901