Adds a sanitize function to host-rules that redacts tokens and passwords from issues and PRs.

Closes #4444

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.

Closes #2028 

Closes #3239 

This deprecates the (internal) use of package URLs and instead replaces with `datasource`/`lookupName`.

Closes #3005 

Rename all VSTS references to be Azure DevOps.

Closes #2810

BREAKING CHANGE: 'vsts' platform is now renamed to 'azure'

Needed for package managers that support more than one depType (e.g. Bundler).

Closes #3076

Helps with https://github.com/renovatebot/renovate/pull/3039  

Adds new filter option “languages” to packageRules to filter on language time.

Adds new filter option `managers` to `packageRules`. This allows you to define rules that filter on package manager (e.g. pipenv) before applying the rule.

Adds filtering option “sourceUrlPrefixes” to allow matching updates based on one or more prefixes. Prefixes could be a full source repo, e.g. https://github.com/renovatebot/presets, or it could be an org prefix like https://github.com/renovatebot/

This will make monorepo groupings easier.

Renames `endpoints` to `hostRules`

Closes #2363