feat(eval api): (2.2/n) delete eval / scoring / scoring_fn apis (#1700)

# What does this PR do?
- To make it easier, delete existing `eval/scoring/scoring_function`
apis. There will be a bunch of broken impls here. The sequence is:
1. migrate benchmark graders
2. clean up existing scoring functions

- Add a skeleton evaluation impl to make tests pass. 

## Test Plan
tested in following PRs

[//]: # (## Documentation)

pyproject.toml

@@ -168,7 +168,6 @@ exclude = [
     "^llama_stack/apis/common/training_types\\.py$",
     "^llama_stack/apis/datasetio/datasetio\\.py$",
     "^llama_stack/apis/datasets/datasets\\.py$",
-    "^llama_stack/apis/eval/eval\\.py$",
     "^llama_stack/apis/files/files\\.py$",
     "^llama_stack/apis/inference/inference\\.py$",
     "^llama_stack/apis/inspect/inspect\\.py$",
@@ -177,8 +176,6 @@ exclude = [
     "^llama_stack/apis/providers/providers\\.py$",
     "^llama_stack/apis/resource\\.py$",
     "^llama_stack/apis/safety/safety\\.py$",
-    "^llama_stack/apis/scoring/scoring\\.py$",
-    "^llama_stack/apis/scoring_functions/scoring_functions\\.py$",
     "^llama_stack/apis/shields/shields\\.py$",
     "^llama_stack/apis/synthetic_data_generation/synthetic_data_generation\\.py$",
     "^llama_stack/apis/telemetry/telemetry\\.py$",
@@ -218,6 +215,7 @@ exclude = [
     "^llama_stack/providers/inline/agents/meta_reference/agent_instance\\.py$",
     "^llama_stack/providers/inline/agents/meta_reference/agents\\.py$",
     "^llama_stack/providers/inline/agents/meta_reference/safety\\.py$",
+    "^llama_stack/providers/inline/evaluation/meta_reference/evaluation\\.py$",
     "^llama_stack/providers/inline/datasetio/localfs/",
     "^llama_stack/providers/inline/eval/meta_reference/eval\\.py$",
     "^llama_stack/providers/inline/inference/meta_reference/config\\.py$",