Review web and http observations and metrics properties

[wilkinsona]

We use a mixture of web and http in the property names at the moment:

• management.metrics.web.client.max-uri-tags
• management.metrics.web.server.max-uri-tags
• management.observations.http.client.requests.name (default is http.client.requests)
• management.observations.http.server.requests.name (default is http.server.requests)

In 4.0, we have an opportunity to consistently use one or the other if we want.