This PR propagates the read coordinator logic so that read timeout and read failure exceptions are propagated without throwing on the coordinator side.
This PR is only concerned with exceptions which were originally thrown by the coordinator (in read resolvers). Exceptions propagated through RPC and RPC timeouts will still throw, although those exceptions will be caught and converted into exceptions-as-values by read resolvers.
This is a continuation of work started in #10014.
Results of `perf_simple_query --smp 1 --operations-per-shard 1000000` (read workload), compared with merge base (10880fb0a7):
```
BEFORE:
125085.13 tps ( 80.2 allocs/op, 12.2 tasks/op, 49010 insns/op)
125645.88 tps ( 80.2 allocs/op, 12.2 tasks/op, 49008 insns/op)
126148.85 tps ( 80.2 allocs/op, 12.2 tasks/op, 49005 insns/op)
126044.40 tps ( 80.2 allocs/op, 12.2 tasks/op, 49005 insns/op)
125799.75 tps ( 80.2 allocs/op, 12.2 tasks/op, 49003 insns/op)
AFTER:
127557.21 tps ( 80.2 allocs/op, 12.2 tasks/op, 49197 insns/op)
127835.98 tps ( 80.2 allocs/op, 12.2 tasks/op, 49198 insns/op)
127749.81 tps ( 80.2 allocs/op, 12.2 tasks/op, 49202 insns/op)
128941.17 tps ( 80.2 allocs/op, 12.2 tasks/op, 49192 insns/op)
129276.15 tps ( 80.2 allocs/op, 12.2 tasks/op, 49182 insns/op)
```
The PR does not introduce additional allocations on the read happy-path. The number of instructions used grows by about 200 insns/op. The increase in TPS is probably just a measurement error.
Closes#10092
* github.com:scylladb/scylla:
indexed_table_select_statement: return some exceptions as exception messages
result_combinators: add result_wrap_unpack
select_statement: return exceptions as errors in execute_without_checking_exception_message
select_statement: return exceptions without throwing in do_execute
select_statement: implement execute_without_checking_exception_message
select_statement: introduce helpers for working with failed results
query_pager: resultify relevant methods
storage_proxy: resultify (do_)query
storage_proxy: resultify query_singular
storage_proxy: propagate failed results through query_partition_key_range
storage_proxy: resultify query_partition_key_range_concurrent
storage_proxy: modify handle_read_error to also handle exception containers
abstract_read_executor: return result from execute()
abstract_read_executor: return and handle result from has_cl()
storage_proxy: resultify handling errors from read-repair
abstract_read_executor::reconcile: resultise handling of data_resolver->done()
abstract_read_executor::execute: resultify handling of data_resolver->done()
result_combinators: add result_discard_value
abstract_read_executor: resultify _result_promise
abstract_read_executor: return result from done()
abstract_read_resolver: fail promises by passing exception as value
abstract_read_resolver: resultify promises
exceptions: make it possible to return read_{timeout,failure}_exception as value
result_try: add as_inner/clone_inner to handle types
result_try: relax ConvertWithTo constraint
exception_container: switch impl to std::shared_ptr and make copyable
result_loop: add result_repeat
result_loop: add result_do_until
result_loop: add result_map_reduce
utils/result: add utilities for checking/creating rebindable results
75fb45df1b