Store Provenance State in Swarm

[ghareeb-falazi]

When exporting a provenance CSAR, all new or edited files since the last
export of the same servicetemplate are stored in the Ethereum Swarm
network.
Furthermore, these files are retrievable on-demand so we can visually show changed
content between any two exported CSARs of the same servicetemplate.
Accountability UI is enhanced and a configuration tab for it is added.

The following UIs were added:

• Configuration: allows configuring the accountability layer. If "Enable Accountability Tracking" is unchecked, other UIs (such as CSAR import and export) will not show any provenance-related options. The option is unchecked by default:

• Authorization and Authentication: allow giving permission to participants to work on a given service template (they should have an Ethereum account to identify them), as well as manually authenticate them. An automatic authentication happens when importing a CSAR which is registered in the accountability layer.

• Provenance: allows visualizing the history of registered (exported) CSAR versions of a specific service template in the context of a collaborative development process. Detailed information can be shown for the CSARs as a whole and for every contained file in them, by allowing the contents of various versions of the same file to be compared.

• Ensure that you followed http://eclipse.github.io/winery/dev/ToolChain#github---prepare-pull-request. Especially, we require a single commit
• Ensure that the commit message is a good commit message
• Ensure to use auto format in all files
• Ensure that you appear in NOTICE at Copyright Holders
• Tests created for changes
• Documentation updated (if needed)
• Screenshots added (for UI changes)

[lharzenetter]

Can you please resolve the merge conflicts?

[lharzenetter]

In general, looks pretty good!
However, please resolve the comments.

[lharzenetter]

Awaiting approval CQ 17598

[lharzenetter]

Merging as of parallel IP.