[DOCS] Re-enable code snippet testing for rollup APIs

[lcawl]

Related to #30665 and #31450

The code snippets in the rollup documentation was disabled because they ceased working after they were moved to the docs folder.

Per #31450 (comment), we need to move RollupRestTestStateCleaner over to the test framework and then use it in the docs tests.

[elasticmachine]

Pinging @elastic/es-search-aggs

[elasticmachine]

Pinging @elastic/es-docs