Implement SQLiteDatabase::Rewrite

Summary:
Rewrite uses the VACUUM command which does exactly what we want. A
specific advertised use case is to compact a database and ensure that
any deleted data is actually deleted.

This is a backport of [[bitcoin/bitcoin#19077 | core#19077]] [15/26]
bitcoin/bitcoin@010e365

Depends on D10562

Test Plan:
With clang-tidy
`ninja`

Reviewers: #bitcoin_abc, deadalnix

Reviewed By: #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D10563

src/wallet/sqlite.cpp

@@ -238,7 +238,10 @@ void SQLiteDatabase::Open() {
 }
 
 bool SQLiteDatabase::Rewrite(const char *skip) {
-    return false;
+    // Rewrite the database using the VACUUM command:
+    // https://sqlite.org/lang_vacuum.html
+    int ret = sqlite3_exec(m_db, "VACUUM", nullptr, nullptr, nullptr);
+    return ret == SQLITE_OK;
 }
 
 bool SQLiteDatabase::Backup(const std::string &dest) const {