iterator: delete TypedRowLendingStream as unusable

[wprzytula]

We failed to find a way to make TypedRowLendingStream usable. The borrow checker keeps forbidding making more than one call to next() method.

In the close future, we'll investigate alternatives to bring borrowed types deserialization capabilities to QueryPager.

Pre-review checklist

• I have split my patch into logically separate commits.
• All commit messages clearly explain what they change and why.
• [ ] I added relevant tests for new features and bug fixes.
• All commits compile, pass static checks and pass test.
• PR description sums up the changes and reasons why they should be introduced.
• [ ] I have provided docstrings for the public items that I want to introduce.
• [ ] I have adjusted the documentation in ./docs/source/.
• [ ] I added appropriate Fixes: annotations to PR description.

[github-actions]

cargo semver-checks detected some API incompatibilities in this PR.
Checked commit: f1dc5b6

See the following report for details:

cargo semver-checks output

./scripts/semver-checks.sh --baseline-rev 814de55d710391cfe6e649b66c16e2b92c4a2a7f
+ cargo semver-checks -p scylla -p scylla-cql --baseline-rev 814de55d710391cfe6e649b66c16e2b92c4a2a7f
     Cloning 814de55d710391cfe6e649b66c16e2b92c4a2a7f
     Parsing scylla v0.14.0 (current)
      Parsed [  28.169s] (current)
     Parsing scylla v0.14.0 (baseline)
      Parsed [  22.764s] (baseline)
    Checking scylla v0.14.0 -> v0.14.0 (no change)
     Checked [   0.118s] 94 checks: 92 pass, 2 fail, 0 warn, 0 skip

--- failure inherent_method_missing: pub method removed or renamed ---

Description:
A publicly-visible method or associated fn is no longer available under its prior name. It may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.36.0/src/lints/inherent_method_missing.ron

Failed in:
  QueryPager::rows_lending_stream, previously in file /home/runner/work/scylla-rust-driver/scylla-rust-driver/target/semver-checks/git-814de55d710391cfe6e649b66c16e2b92c4a2a7f/53995b156e5bf29b0d33e08f437c41da85f6e2a7/scylla/src/transport/iterator.rs:652

--- failure struct_missing: pub struct removed or renamed ---

Description:
A publicly-visible struct cannot be imported by its prior path. A `pub use` may have been removed, or the struct itself may have been renamed or removed entirely.
        ref: https://doc.rust-lang.org/cargo/reference/semver.html#item-remove
       impl: https://github.com/obi1kenobi/cargo-semver-checks/tree/v0.36.0/src/lints/struct_missing.ron

Failed in:
  struct scylla::transport::iterator::TypedRowLendingStream, previously in file /home/runner/work/scylla-rust-driver/scylla-rust-driver/target/semver-checks/git-814de55d710391cfe6e649b66c16e2b92c4a2a7f/53995b156e5bf29b0d33e08f437c41da85f6e2a7/scylla/src/transport/iterator.rs:989

     Summary semver requires new major version: 2 major and 0 minor checks failed
    Finished [  51.107s] scylla
     Parsing scylla-cql v0.3.0 (current)
      Parsed [  11.299s] (current)
     Parsing scylla-cql v0.3.0 (baseline)
      Parsed [  11.284s] (baseline)
    Checking scylla-cql v0.3.0 -> v0.3.0 (no change)
     Checked [   0.106s] 94 checks: 94 pass, 0 skip
     Summary no semver update required
    Finished [  22.738s] scylla-cql
make: *** [Makefile:61: semver-rev] Error 1

[Lorak-mmk]

Its surprising how bad is the diff generated by GitHub