Previously, the MiniYaml.From* helpers such as FromStream would consume the entire input and then return a list of top-level nodes. Now, the input is processed using deferred execution and top-level nodes are yielded as they are resolved from the input.
The motivating use-case is MapCache, which currently manually buffers nodes before passing to MiniYaml.FromString in order to improve responsiveness when large payloads are processed. Now that MiniYaml.FromStream yields results back as they come in, we can switch to that without disadvantage.
The maintains the performance where map cache can update search results as each node comes in over the network rather than having to wait for the entire batch to be transferred. Now we can also remove the string buffer that captures each node, reducing memory pressure and simplifying the code.
