Revert stream default semantics to not wait for Rust function execution; Allow users to customize whether to await for Rust function for streams

[fzyzcjy]

Changes

Fix #1874 Fix #1873

Checklist

• [ ] An issue to be fixed by this PR is listed above.
• [ ] New tests are added to ensure new features are working. Please refer to this page to see how to add a test.
• [ ] ./frb_internal precommit --mode slow (or fast) is run (it internal runs code generator, does auto formatting, etc).
• [ ] If this PR adds/changes features, documentations (in the ./website folder) are updated.
• [ ] CI is passing. Please refer to this page to see how to solve a failed CI.

Remark for PR creator

• ./frb_internal --help shows utilities for development.
• If fzyzcjy does not reply for a few days, maybe he just did not see it, so please ping him.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 99.27%. Comparing base (1d7285a) to head (1469ec6).

:exclamation: Current head 1469ec6 differs from pull request most recent head 51a8a46. Consider uploading reports for the commit 51a8a46 to get more accurate results

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #1877 +/- ## ======================================= Coverage 99.27% 99.27% ======================================= Files 365 365 Lines 15431 15447 +16 ======================================= + Hits 15319 15335 +16 Misses 112 112 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.