Create a small library for ObjectFactory, since it is a dependency of ObjectCache/{T146257}
* [x] Create repo, bootstrap with [mediawiki/tools/cookiecutter-library](https://phabricator.wikimedia.org/diffusion/MCCL/)
* [x] Set up Jenkins jobs:
- [x] composer-test for patch and submit pipeline (use `composer-test-package` template in zuul/layout)
- [x] publish Doxygen
- [x] publish Coverage
* [x] Initial import of code, tests, and documentation.
- [x] Use PSR-4 autoloader
- [x] Use "Wikimedia" namespace
- [x] phpcs
- [x] phpunit
* [x] Publish composer package to Packagist, under `wikimedia/`.
* [x] Add documentation link to https://doc.wikimedia.org.
* [ ] Ensure Gerrit-Phabricator replication.
* [x] Ensure Gerrit-GitHub replication.
* [ ] Create Phabricator project for bugs
* [ ] Create documentation page on mediawiki.org. <https://www.mediawiki.org/wiki/ObjectFactory>
- Link to code on Phab: TODO
- Link to code on GitHub: <https://github.com/wikimedia/ObjectFactory>
- Link to Packagist package: Done
- Link to Doxygen output: Done
* [x] Update mediawiki/core to use the package.