Co-Authored-By: Michael Kriese <michael.kriese@visualon.de>

Ref #5555

If a pypi package:
 - Has only src releases
 - Has an index name with hyphens
 - Has src tarballs with underscores
Then releases of the package weren't being detected.

Devpi preprends a `+` before simple indices. This commit adds support
for them.

Closes #4507

Closes #4047

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

Closes #2970 

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

Closes #3005 

Wraps the `got` library in our own wrapper to add:
- Renovate user agent
- Memory cache wrapper

* add filter and sort to datasource
* remove filter and sort from individual datasources

When including basic-auth information in the URL, such as
`https://user:pass@my.pypi.repo.xx/repo`, `got` needs this url-parsed to
not throw an error. Since this is common with requirement.txts and
Pipfiles, let’s support this.

Closes #2971

Provide a central location for mapping changelog and source URLs.

Simplify when statically selected

add firebase-admin release notes