test: restore conf units pasted into operator_conf_and_argv

[rearden-grok]

Summary

Part of #1022 and most of #1023 moved conf checks into operator_conf_and_argv without sharing that journey's setup or moving them off private accessors.

• Restored as their own tests: the test: fold conf fields and mempool rejects onto existing journeys #1022 concatenations (electrum_max_subs_cli_conf_and_bounds, max_sh_creates_and_esplora_block_template_cli_hyphens, conf_error_names_the_file_and_line, check_blocks_apply_kv_zero_is_all, prefillcompact_cli_conf_default_on) and the test: fold conf apply_kv setters onto operator_conf_and_argv #1023 NodeConfig::default() / apply_kv blocks (tor_control_password_rejects_a_line_break, apply_kv_is_the_conf_setter_and_unknown_is_not_error, rpc_socket_moves_the_socket_out_of_the_datadir, blocks_dir_is_not_an_operator_key, duplicate_listen_is_init_error). Restoring apply_kv also puts back cases the paste dropped: network=regtest, unknown checkblocks / prefillcompact, and the max-sh / esplora flag matrix.
• Left in place: rpc_work_queue default, 0, and 4 now go through ready_config argv, which is the surface this journey already uses. The six mempool and sigop deletions from test: fold conf fields and mempool rejects onto existing journeys #1022 stay deleted. mempool_accept_life and sigop_adjusted_size_budget_and_reopen already asserted those errors and sigop counts, and test: fold conf fields and mempool rejects onto existing journeys #1022 did not paste those bodies into the journeys.
• --check-blocks and --prefill-compact argv asserts that were already on the journey stay there.

Test-only. No changelog.

Test plan

• cargo fmt -p rbitcoin-node
• cargo clippy -p rbitcoin-node --lib --tests -- -D warnings
• filtered rbitcoin-node lib tests for the restored names and cli::tests (16 passed)
• GitHub qc, test, windows, macos, coverage