Consume ni-apis-python packages

[dixonjoel]

• This contribution adheres to CONTRIBUTING.md.

What does this Pull Request accomplish?

• Use ni-grpc-extensions package
• Use ni.measurementlink.discovery.v1.client
• Use ni.measurementlink.sessionmanagement.v1.client

Why should this Pull Request be merged?

Clear out second source for this code and use the official package(s).

What testing has been done?

Repo tests should be sufficient.

[github-actions]

Test Results

    52 files  ±  0      52 suites  ±0   1h 14m 13s ⏱️ - 3m 36s
   689 tests  -  24     689 ✅  -  24      0 💤 ± 0  0 ❌ ±0 
20 700 runs   - 864  19 644 ✅  - 844  1 056 💤  - 20  0 ❌ ±0 

Results for commit a071877. ± Comparison against base commit 26f3b99.

This pull request removes 24 tests.

tests.unit.test_discovery_client ‑ test___discovery_service_exe_unavailable___register_service___raises_file_not_found_error
tests.unit.test_discovery_client ‑ test___discovery_service_not_running___get_discovery_service_address___starts_discovery_service
tests.unit.test_discovery_client ‑ test___enumerate_compute_nodes___grpc_error___raises_rpc_error
tests.unit.test_discovery_client ‑ test___key_file_exist_after_poll___start_discovery_service___discovery_service_started
tests.unit.test_discovery_client ‑ test___key_file_never_created___get_discovery_service_address___throws_timeout_error
tests.unit.test_discovery_client ‑ test___key_file_not_exist___open_key_file___raises_file_not_found_error[2]
tests.unit.test_discovery_client ‑ test___key_file_not_exist___open_key_file___raises_file_not_found_error[3]
tests.unit.test_discovery_client ‑ test___multiple_registered_compute_nodes___enumerate_compute_nodes___returns_all_nodes
tests.unit.test_discovery_client ‑ test___no_registered_compute_nodes___enumerate_compute_nodes___returns_empty_list
tests.unit.test_discovery_client ‑ test___no_registered_measurements___enumerate_services___returns_empty_list
…

♻️ This comment has been updated with latest results.

[csjall]

Approved once system tests are passing.