Extract constants for all command names
Updated store-report command to a multimethod

We will need to support multiple versions of the store-report
command for Burgundy since we're changing the wire format.

This commit simply re-works the existing store report command
to use a multimethod, and introduces v1 of the multimethod.
This commit does not introduce a v2 implementation of the
multimethod yet.
Introduce v2 of store-report command
(PE-959) Save resource event file/line properties

Prior to this commit, the file and line properties that exist on a
resource event were not being saved down to PuppetDB during report
processing. This commit changes that so we can show that information
in Burgundy.
Bump up report version to 2
Use file/line even during skipped events
Bump up report format in exporter
Anonymize source file/line
Comment cleanup and add validation precondition
Event query endpoint file/line documentation
Merge pull request #600 from shakedown/dev/master/pe959-file-line-stuff

(PE-959) Store file/line information