Provide access to router within web container by hostname, fixes #842

[rfay]

The Problem/Issue/Bug:

Various web projects require http/s access to the project by the projects scheme/name/port from within the web container, which means they have to go through the router. OP #842

How this PR Solves The Problem:

Provide access to the router using docker-compose.yaml

Manual Testing Instructions:

• Start a project
• ddev ssh
• Use curl <fqdn> to view the project.

For extra credit, use the https URL and use configurable ports. For https you'll need to use curl -k.

Automated Testing Overview:

• Added TestInternalAndExternalAccessToURL(). This tests external and internal url access with a content test and also tests with nonstandard ports
• Reorganized site definition to not only get a safe static URL to hit but also check the returned content.

Related Issue Link(s):

OP #842

Release/Deployment notes:

[rfay]

This requires documentation for various external services that may want to access the web container by URL.

[andrewfrench]

I was able to configure an FQDN, ddev start, ddev ssh, curl <fqdn>, and run ping <fqdn>. Curl returned the local d7 install page as expected, and the FQDN resolved to localhost through ping.