History/cache: add search options endpoints and extend project cache

[ol-nata]

Info

This PR adds two new GET endpoints to HistoryViewSet for populating search option dropdowns on the history page. It also extends the project cache to cover branches, revisions, and labels alongside tags, so that metas_search_options can serve responses without hitting the database.

Overview of changes

Cache

_TagsCache is replaced with _MetasCache, which stores tags, branches, revisions, and labels under separate keys. All call sites updated accordingly.

API

GET /bublik/api/v2/history/params_search_options/

Returns available parameter name/value pairs for a given test, for use in search option dropdowns.

Query parameters:

• test_name (string; required) — test name or full path
• project (integer; optional) — project ID to filter results

Response data:

["param1=value1", "param1=value2", "param2=value1"]

GET /bublik/api/v2/history/metas_search_options/

Returns available tags, branches, revisions, and labels, for use in search option dropdowns.

Query parameters:

• project (integer; optional) — project ID to filter results

Response data:

{
    "tags": {
        "important": ["tag1=val1"],
        "relevant": ["tag2=val2"],
        "all": ["tag1=val1", "tag2=val2"]
    },
    "branches": ["branch=main"],
    "revisions": ["revision=abc123"],
    "labels": ["label=nightly"]
}