[feat] rework schema_validator on plugin utils and load_config

[Aliaksei-Kharlap]

Moves schema_validator onto influxdata-plugin-utils 0.5.0

Utils instead of local copies

| Was in the plugin | Now |
| _LineBuilderInterface, _BatchLines | write.write_data |
| _add_typed_field, _add_inferred_field | write.build_line_typed, write.infer_type |
| tomllib + pathlib config reader | sources.parse_toml, sources.parse_trigger_args, config.resolve_path |
| hand-rolled setting checks | validation.Validator |
| hand-rolled influxdb3_local.cache.get/put | cache.cached, five-minute TTL |

Config

• the TOML file overrides the trigger arguments key by key instead of replacing
  them; a key the file leaves out keeps the value the arguments gave it
• one KeySpec allowlist, built from the validators, refuses an unknown key in
  both layers instead of dropping it

Fixed

• a target equal to its source no longer feeds the trigger back into itself
• an unknown field type is named, with the accepted types listed
• a non-finite value rejects its row instead of dropping the table's write
• one table's write failure no longer discards the others; counters follow writes
• type: "float" no longer accepts a bool
• a table with no fields is refused at schema load
• schema and config errors keep their cause
• the rejection log is batched, with strictly increasing timestamps