[VIRTS-2798] Operation Link Results Endpoint

[bleepbop]

Description

Created new endpoint GET /operations/{id}/links/{link_id}/result.
In the v1 api, there was an endpoint for fetching encoded link results (rest_svc.display_result()). We didn't have this in the api v2 design, but it's necessary as some abilities don't have parsers, preventing some results from being added to link objects as facts.

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

Tested using Postman, comparing output to v1 API. Also included Pytest unit tests for this endpoint; the rest of the operation pytests will be merged in a separate PR.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works

[uruwhy]

Let's add a pytest unit test as well to make sure the behavior works as expected - you can try mocking the read_result_file method for the file service to avoid having to read/write files on disk

[codecov]

Codecov Report

Merging #2239 (b9638f0) into master (952bf78) will decrease coverage by 0.69%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2239      +/-   ##
==========================================
- Coverage   67.74%   67.04%   -0.70%     
==========================================
  Files          90       92       +2     
  Lines        6963     7286     +323     
==========================================
+ Hits         4717     4885     +168     
- Misses       2246     2401     +155     

Impacted Files	Coverage Δ
app/api/v2/handlers/operation_api.py	61.76% <100.00%> (ø)
app/api/v2/managers/operation_api_manager.py	29.41% <100.00%> (ø)
app/service/app_svc.py	50.28% <0.00%> (+0.57%)	⬆️
app/objects/c_operation.py	71.42% <0.00%> (+1.68%)	⬆️
app/objects/c_planner.py	88.88% <0.00%> (+1.85%)	⬆️
app/api/v2/handlers/base_api.py	70.96% <0.00%> (+3.22%)	⬆️
app/api/v2/responses.py	86.11% <0.00%> (+16.66%)	⬆️
app/objects/c_source.py	86.84% <0.00%> (+17.10%)	⬆️
... and 1 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 952bf78...b9638f0. Read the comment docs.

[bleepbop]

Let's add a pytest unit test as well to make sure the behavior works as expected - you can try mocking the read_result_file method for the file service to avoid having to read/write files on disk

Added fixtures from operations api pytests, along with tests for the new endpoint

[uruwhy]

Looks good!

[iguannalin]

Tested with UI--the endpoint is only called when link output is "True" and the returned result is decoded and displayed to the user. LGTM!