Migrate search documentation/references/examples to query

[timvisee]

We still showed our search API in many places. This PR migrates it to use the query API instead.

This primarily:

• replaces search example on documentation front page with query (versus current):

• replaces examples/search.rs with examples/query.rs
  

  rust-client/examples/query.rs

  Lines 54 to 78 in 8e083f3

  	let query_result = client
  	.query(
  	QueryPointsBuilder::new(collection_name)
  	.query(vec![11.0; 10])
  	.limit(10)
  	.filter(Filter::all([Condition::matches("bar", 12)]))
  	.with_payload(true)
  	.params(SearchParamsBuilder::default().exact(true)),
  	)
  	.await?;
  	dbg!(&query_result);
  	// query_result = [
  	// {
  	// "id": 0,
  	// "version": 0,
  	// "score": 1.0000001,
  	// "payload": {
  	// "bar": 12,
  	// "baz": {
  	// "qux": "quux"
  	// },
  	// "foo": "Bar"
  	// }
  	// }
  	// ]

• some other minor changes to hint and use query instead

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