Update PW-RPC service to use DataModel::Provider for writes (#37160)

* Avoid PW-RPC assertion error if application is stopped without any RPC connections

* Anoter PWRPC crash fix

* Implement the write from TLV

* Update protos to support string and bytes as separate types for encode/decode

* Restyle

* make writes actually work

* Make write(read.tlv) actually work

* Fix typo

Author: andy31415

examples/common/pigweed/protos/attributes_service.options

@@ -1,3 +1,4 @@
 
 chip.rpc.AttributeData.data_bytes max_size:128
+chip.rpc.AttributeData.data_string max_size:128
 chip.rpc.AttributeData.tlv_data max_size:256