Use defined error constants throughout codebase.

GitLab self-hosted users now no longer need to manually configure gitAuthor if it matches with the bot account they’re using.

Rewrites hostRules for increased flexibility. Includes renames of existing fields within a hostRule:
- `endpoint` -> `baseUrl`
- `host` -> `hostName`

Additionally, `domainName` has been added. Migration scripts should take care of these for users but it's recommended to update configs to match the new fields anyway.

Refactors hostRules to use field “hostType” instead of “platform”. hostType can include datasources like npm, maven, pypi, etc.

The gitlab platform is now implemented using gitFs over http/https. Ensure you are using a Personal Access Token with “api” scope. Remove any custom “gitFs” config option now - it will be autodetected based on the endpoint value. For most - maybe all - users, there should not be any change required at all.

Closes #3478

BREAKING CHANGE: gitlab platform is now gitFs only and requires a Personal Access Token with api scope.

Adds ability to use a GitLab OAuth2 token by settings oauth=true in admin config.

Renames `endpoints` to `hostRules`

Retries every minute up to 5 times if receiving 429 from gitlab.

Closes #1578

Adds option for useCache to github and gitlab wrappers.

This reverts commit 04e0ca1f.

Refactors credentials/token handling to rely less on env variables and instead use an endpoints middleware for credentials handling.

First step towards #2105

This reverts commit dd26a018.

Refactors all instances of .concat() to use array spread operators instead

Closes #1459

This PR ports across GitHub’s caching approach to the GitLab platform API.

Refactors file system of platforms and adds test to ensure GitHub and GitLab have same module.exports signatures.

Adds paginated results capability for gitlab and enables it for getFileList. This should enable all files when using APIv4.

Hopeful this c-l-o-s-e-s #962 & #968