webassembly: investigate remote database access

Many applications make use of databases such as MySQL and PostgresSQL for data storage, where the applications makes a connection to a database server over the network, most likely using a tcp socket . It is desirable that these applications can do this also when built for WebAssembly.

Qt provides database drivers but these depend on the database client libraries. Getting this working then requires:

• porting the client library in question to webassembly (adding a wasm platform target)
• networking: tcp tunneling using websockify?