Investigate uploading legacy JARs

[GCHQDeveloper314]

Accumulo 2 became the default version of Accumulo in Gaffer in #2679. Accumulo 1 support was retained with a legacy profile. The shaded JARs created with this profile (e.g. spring-rest exec, accumulo-store iterators) differ from the standard shaded JARs because they contain supporting libraries for Accumulo 1. These JARs have a -legacy classifier added to their filenames.

Currently we're not uploading these JARs. A separate build of Gaffer needs to be run in order to create them, this would require changes to the CI. The current plugin used to upload cannot be used for these JARs because it would also upload all the other jars which do not have the classifier; these JARs would already exist as part of the build and overwriting is not supported.

One possible solution would be to to use the deploy-file goal of the maven-deploy-plugin to manually deploy each of the legacy JARs.