Issue

Problem to solve
Codecov has never had a way of knowing conclusively when a user has finished uploading coverage reports. This means that sometimes we send a PR comment before it's desired and calculate results before they're 100% accurate regarding all coverage for that commit.

Proposed Solution
Create a manual trigger that allows users to signal when they have completed uploading reports for a specific commit using the Codecov CLI. This requires extending the UploadFinisher task to prevent notifications for regular uploads, and integrating the manual trigger into the CLI. This will streamline the report submission process and enhance the user experience for Codecov CLI users.