feat(sqlite): add bdk_sqlite crate implementing PersistBackend backed by a SQLite database

crates/sqlite/schema/schema_0.sql

@@ -0,0 +1,69 @@
+-- schema version control
+CREATE TABLE version
+(
+    version INTEGER
+) STRICT;
+INSERT INTO version
+VALUES (1);
+
+-- network is the valid network for all other table data
+CREATE TABLE network
+(
+    name TEXT UNIQUE NOT NULL
+) STRICT;
+
+-- keychain is the json serialized keychain structure as JSONB,
+-- descriptor is the complete descriptor string,
+-- descriptor_id is a sha256::Hash id of the descriptor string w/o the checksum,
+-- last revealed index is a u32
+CREATE TABLE keychain
+(
+    keychain      BLOB PRIMARY KEY NOT NULL,
+    descriptor    TEXT             NOT NULL,
+    descriptor_id BLOB             NOT NULL,
+    last_revealed INTEGER
+) STRICT;
+
+-- hash is block hash hex string,
+-- block height is a u32,
+CREATE TABLE block
+(
+    hash   TEXT PRIMARY KEY NOT NULL,
+    height INTEGER          NOT NULL
+) STRICT;
+
+-- txid is transaction hash hex string (reversed)
+-- whole_tx is a consensus encoded transaction,
+-- last seen is a u64 unix epoch seconds
+CREATE TABLE tx
+(
+    txid      TEXT PRIMARY KEY NOT NULL,
+    whole_tx  BLOB,
+    last_seen INTEGER
+) STRICT;
+
+-- Outpoint txid hash hex string (reversed)
+-- Outpoint vout
+-- TxOut value as SATs
+-- TxOut script consensus encoded
+CREATE TABLE txout
+(
+    txid   TEXT    NOT NULL,
+    vout   INTEGER NOT NULL,
+    value  INTEGER NOT NULL,
+    script BLOB    NOT NULL,
+    PRIMARY KEY (txid, vout)
+) STRICT;
+
+-- join table between anchor and tx
+-- block hash hex string
+-- anchor is a json serialized Anchor structure as JSONB,
+-- txid is transaction hash hex string (reversed)
+CREATE TABLE anchor_tx
+(
+    block_hash          TEXT NOT NULL,
+    anchor              BLOB NOT NULL,
+    txid                TEXT NOT NULL REFERENCES tx (txid),
+    UNIQUE (anchor, txid),
+    FOREIGN KEY (block_hash) REFERENCES block(hash)
+) STRICT;