System Test: add coverage on CLI generated typescript bindings

[sreuland]

What problem does your feature solve?

the tests don't exercise the cli generated ts bindings for a contract which are created from soroban contract bindings typescript --wasm

What would you like to see?

• a new test scenario for generated ts bindings.
  • generate the ts bindings from the compiled wasm of the soroban-examples increment contract using cli command soroban contract bindings typescript --wasm.
  • run a ts script that imports the generated bindings.
  • the ts script invokes the increment contract method and verifies the invocation result using the generated bindings.

What alternatives are there?