better example style (rust + wasm)

[eike-hass]

Principles:
lower number examples should introduce a principle
higher number examples should re-use it (or use a helper function with the same content)

• Align naming, logging and flow between examples and languages
• Add example to use Identity object with IOTA SDK
  • Idea:
    1. Create Asset/Coin? using IOTA SDK
    2. Transfer to (Identity) Object
    3. Access transferred Object using borrow proposal
• Demonstrate difference between localnet and wellknown networks
  • remove package ID from examples/README.md
• Multi control example
  • Idea:
    1. Create single controller identity
    2. Add second controller
    3. Demonstrate threshold process
• Also consider splitting up the helper functions into separate files, which might make the references from the wiki to the example code less affected by line number changes. Bonus questions:
  • Could we just insert a reference to the entire file? (less hassle to maintain)
  • Would the repeated license header in the wiki in that case be okay or just visual noise?