Return error on misuse

While the library is designed to be used from applications,
it is often very convenient to allow interactive use.

Panic is the wrong answer there, so returning an error instead.

Add int64 driver support

The int64 type is often used for timestamps, using it natively reduce
boilerplate for the library user.

The new `testing/synctest` package makes timeout testing a breeze

Automatically free connection on iteration error

Allow multiple calls for Err

Remove virtual table wrapper

Virtual tables are a powerful extension to SQLite, but the interaction
with the Go runtime is all but trivial. The bridge does not do enough
to protect the results, so removing it.

Modernize the memory management around Go functions.

Update to Go 1.25

Use simple transaction for connection pool

The use of the advanced Savepoint / Release in the library led to having complicated
(and usually incorrect) code on the caller site.

Instead, offer a lighter mechanism to execute multiple statements together by exporting
a connection carrying the transaction.
The full savepoint / release is still available through statements.

Update SQLite amalgamation

Handle json decoding

Create backup if does not exist