[ref] gva_dbs_reader: create trait DbsReader

Cargo.lock

rust-libs/duniter-dbs/Cargo.toml

rust-libs/modules/gva/Cargo.toml

rust-libs/modules/gva/bca/Cargo.toml

...dules/gva/bca/src/exec_req_type/prepare_simple_payment.rs

rust-libs/modules/gva/bca/src/lib.rs

rust-libs/modules/gva/dbs-reader/Cargo.toml

rust-libs/modules/gva/dbs-reader/src/block.rs

rust-libs/modules/gva/dbs-reader/src/current_frame.rs

rust-libs/modules/gva/dbs-reader/src/find_inputs.rs

rust-libs/modules/gva/dbs-reader/src/idty.rs

rust-libs/modules/gva/dbs-reader/src/lib.rs

rust-libs/modules/gva/dbs-reader/src/txs_history.rs

rust-libs/modules/gva/dbs-reader/src/uds_of_pubkey.rs

rust-libs/modules/gva/dbs-reader/src/utxos.rs

rust-libs/modules/gva/gql/Cargo.toml

rust-libs/modules/gva/gql/src/lib.rs

rust-libs/modules/gva/gql/src/schema.rs

rust-libs/tools/kv_typed/Cargo.toml