test: Enable single shard tracking and add chunk validators in reshar…

…ding tests (#12621)

- Add test configuration to set number of chunk validators and RPC nodes
- Switch test default to use single shard tracking and stateless
validation
- Use RPC node to submit transactions where possible

Some tests pass only with "workarounds", notably:
- `test_resharding_v3_delayed_receipts_*`, `test_resharding_v3_yield_*`,
`test_resharding_v3_split_parent_buffered_receipts_base` and
`test_resharding_v3_outgoing_receipts_from_splitted_shard` need RPC
disabled and nodes tracking all shards
- `test_resharding_v3_load_mem_trie_*` need nodes to track all shards