Add near-workspaces tests to test/demo some of the examples

[dj8yfo]

Some of the examples are tested via only private interface, and not tested against a live sandbox node

• uncomment previsously #[ignore]-d assertions
  • examples/adder/src/lib.rs
    • https://github.com/dj8yfo/near-sdk-rs/blob/b4b3dff0ef5a3f30841348a80461efc56f97945f/examples/adder/src/lib.rs#L63-L85
• add tests/demonstration of example's logic via running in sandbox near_workspaces and contract's public interface
  • examples/versioned/src/lib.rs
    • https://github.com/dj8yfo/near-sdk-rs/blob/b4b3dff0ef5a3f30841348a80461efc56f97945f/examples/versioned/src/lib.rs?plain=1#L166
  • examples/mission-control/src/mission_control.rs:102
    • https://github.com/dj8yfo/near-sdk-rs/blob/b4b3dff0ef5a3f30841348a80461efc56f97945f/examples/mission-control/src/mission_control.rs?plain=1#L120
  • examples/test-contract/src/lib.rs:50
    • https://github.com/dj8yfo/near-sdk-rs/blob/b4b3dff0ef5a3f30841348a80461efc56f97945f/examples/test-contract/src/lib.rs?plain=1#L68
  • examples/status-message/src/lib.rs:76
    • https://github.com/dj8yfo/near-sdk-rs/blob/b4b3dff0ef5a3f30841348a80461efc56f97945f/examples/status-message/src/lib.rs?plain=1#L94

Each individual example can be addressed separately via a separate pr.
This task can be picked up after #1253 is merged