update 3_3_5_publishing_and_using_data_apps

[rizktouma]

• Modified process description
• Added figures and links to other sections

[rizktouma]

Main modifications to 3.3.5:

• Renamed "Data App Certification" process to "Data App Publication" process given that the certification is only an optional first step of the process
• Added "Find Data App" subprocess figure based on "Query IDS Metadata Broker" process in 3.3.2 Data Offering

Clarification needed:

• Is "Contract Negotiation" part of the "Use Data App" or "Find Data App" subprocess? Is the process still similar to the "Data Exchange" process as indicated in the original text? The latest version of Data Exchange in the master branch (3_3_4_Exchanging_Data.md) includes "Contract Negotiation". Does that mean that "Use Data App" process includes Contract Negotiation as well?
• Revise "Retrieve Data App" subprocess: the original text in the master branch says that it is "conceptually identical with the “Invoke Data Operation” process". Is this still true? The Invoke Data Operation process requires direct communication between Provider and Consumer, is that true to retrieve a data app? Isn't the app retrieved directly by the App User from the App Store without communication with the App Provider? Also, there's no figure specific to the "Invoke Data Operation" process in the master branch yet.

[rizktouma]

Thanks for your contribution. I appriciate the figures very much!

There is already an open PR for section 3.3.5: #145 Would be nice to merge both PRs! Maybe you can integrate your input directly to the branch.

@HeinrichPet Should I wait for a new review or integrate my input already? How should I deal with conflicts (e.g. different figures for same process / architecture)?

[rizktouma]

All figures and process description changes merged into #145