Source `uninstall.fish` file before emitting event
Source `uninstall.fish` file before emitting event

Instead of having every plugin function inside the same file, which
increases the loading time unnecessarily and is not fishy, source the
`uninstall.fish` file for the plugin before the `uninstall_$plugin_name`
event is emitted.

nwykes/oh-my-fish,lfiolhais/oh-my-fish,hfs/oh-my-fish,bobthecow/oh-my-fish,wangyung/oh-my-fish,wangyung/oh-my-fish,hfs/oh-my-fish,oranja/oh-my-fish,eugenesvk/oh-my-fish,eugenesvk/oh-my-fish,bsott/oh-my-fish,oranja/oh-my-fish,nwykes/oh-my-fish,Pyppe/oh-my-fish,wfscheper/oh-my-fish,jeremiejig/oh-my-fish,scorphus/oh-my-fish,oh-my-fish/oh-my-fish,jeremiejig/oh-my-fish,lfiolhais/oh-my-fish,wfscheper/oh-my-fish,bsott/oh-my-fish,oh-my-fish/oh-my-fish,sheldon/oh-my-fish,scorphus/oh-my-fish,MaicoTimmerman/oh-my-fish,MaicoTimmerman/oh-my-fish