feat: generate evaluation test dataset

[bjwswang]

What type of PR is this?

/kind feat

What this PR does / why we need it

Which issue(s) this PR fixes

Fixes #494

Special notes for your reviewer

To generate test dataset for a evaluation, I add a new command arctl eval gen_test_dataset
Usge:

(base) ➜  arcadia git:(evaluation) ✗ ./bin/arctl eval gen_test_dataset -h
Generate a test dataset for evaluation

Usage:
  arctl eval gen_test_dataset [flags]

Flags:
      --ground-truths-column string   The column name which provides the answers (default "a")
  -h, --help                          help for gen_test_dataset
      --input-dir string              The input directory where to load original dataset files
      --output string                 The way to output the generated dataset rows.We support two ways: 
                                       - stdout: print row 
                                       - csv: save row to csv file
      --question-column string        The column name which provides questions (default "q")

Global Flags:
      --application string   The evaluation task(RAG Evaluation CR Name) name
      --home string          home directory to use (default "/home/bjwswang/.arcadia")
  -n, --namespace string     namespace to use (default "default")

To make it simple ,this command converts the QA CSV which has been generated by dataprocessing to ragas csv dataset files with columens question,ground_truths,answers,contexts via the appruntime

Changelogs:

1. rename pkg/application to pkg/appruntime
   • set namespace to context in NewAppOrGetFromCache and app.Run(
2. add pkg/evaluation to implement evaluation functionalities
3. update CLI arctl:
   • add new command eval
   • remove deprecated commands chat and datasets
   • fix variables pass bugs

[bjwswang]

@Lanture1064 Please verify the test dataset generated by this pr.