Fix bug in new streaming approach, during certain action of adding a definition

[Venryx]

panic
called Result::unwrap() on an Err value: @type:text @val_as_text:""

Caused by:
Error("trailing characters", line: 1, column: 189)

Stack backtrace:
0: anyhow::kind::Adhoc::new
1: rust_shared::utils::errors::to_anyhow
2: app_server::links::pgclient_::wal_structs::data_tuple_entry_to_json_value
3: app_server::links::pgclient_::wal_structs::wal_data_tuple_to_row_data
4: app_server::links::pgclient::start_streaming_changes::{{closure}}::{{closure}}
5: tokio::loom::std::unsafe_cell::UnsafeCell::with_mut
6: tokio::runtime::task::core::Core<T,S>::poll
7: tokio::runtime::task::harness::Harness<T,S>::poll
8: tokio::runtime::scheduler::multi_thread::worker::Context::run_task
9: tokio::runtime::scheduler::multi_thread::worker::Context::run
10: tokio::macros::scoped_tls::ScopedKey::set
11: tokio::runtime::scheduler::multi_thread::worker::run
12: tokio::runtime::task::core::Core<T,S>::poll
13: tokio::runtime::task::harness::Harness<T,S>::poll
14: tokio::runtime::blocking::pool::Inner::run
15: std::sys_common::backtrace::__rust_begin_short_backtrace
16: core::ops::function::FnOnce::call_once{{vtable.shim}}
17: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce>::call_once
at /rustc/c373194cb6d882dc455a588bcc29c92a96b50252/library/alloc/src/boxed.rs:1985:9
18: <alloc::boxed::Box<F,A> as core::ops::function::FnOnce>::call_once
at /rustc/c373194cb6d882dc455a588bcc29c92a96b50252/library/alloc/src/boxed.rs:1985:9
19: std::sys::unix::thread::Thread::new::thread_start
at /rustc/c373194cb6d882dc455a588bcc29c92a96b50252/library/std/src/sys/unix/thread.rs:108:17
20:
21: