Function block_on 

pub fn block_on<F>(fut: F) -> Result<<F as Future>::Output, AsyncError>
where
    F: Future + Send + 'static,
    <F as Future>::Output: Send,

Blocks on the provided future and returns the result.

This function is used to call async functions from sync code.

Due to limitations of tokio runtime, we cannot use tokio::runtime::Runtime::block_on if we are already inside a tokio runtime. This function is a workaround for that limitation.

Handles three scenarios:

• No active runtime: creates a temporary current-thread runtime and drives the future directly.
• Current-thread runtime: spawns a dedicated OS thread with its own independent runtime, since block_in_place panics when there are no other worker threads.
• Any other runtime flavor (multi-thread, etc.): uses block_in_place + spawn for efficient bridging.