Rename pulp services

[lubosmj]

closes #4554
https://pulp.plan.io/issues/4554

[mikedep333]

In addition to my inline comment:

1. Is the pulp-content script (that gets installed in the bin dir) going to stay the same name?
2. Do we need to update the pulp/pulp container image & operator as well? The interface between the operator and the container image is command strings like "pulp-content". I do not feel this is necessary, but it would make things more consistent. It is not necessary because the image / operator exists solely for running pulp3. It would also be extra work because we are not auto-publishing pulp / pulpcore images yet (it's high on my TODO list.)
3. Are we going to rename the roles?

[goosemania]

I submitted another PR #170 with an additional commit on top of this one to rename pulpcore-content-app to pulpcore-content.

I'm not updating other related PRs (docs) until there is an agreement that no other changes are needed.

[dkliban]

In addition to my inline comment:

1. Is the `pulp-content` script (that gets installed in the bin dir) going to stay the same name?

This script should be called pulpcore-content.

2. Do we need to update the pulp/pulp container image & operator as well? The interface between the operator and the container image is command strings like "pulp-content". I do not feel this is necessary, but it would make things more consistent. It is not necessary because the image / operator exists solely for running pulp3. It would also be extra work because we are not auto-publishing pulp / pulpcore images yet (it's high on my TODO list.)

We should create a task in pulp.plan.io for this work, but it can be done later.

3. Are we going to rename the roles?

Let's open a ticket in pulp.plan.io to rename the roles and do it soon after this is merged.

[mikedep333]

@goosemania Good enough, thank you.

@dkliban We'll discuss renaming this script in IRC, or the ticket.

[dralley]

If the new work is done in #170 then this PR should be closed probably