Enable dbstat table by default

[pawurb]

Hi. Similar to TryGhost/node-sqlite3#1279 . This PR enables dbstat table, that contains useful info like size of tables, indexes, etc. useful for debugging.

[flavorjones]

Nice! Thank you for opening this.

Documentation on DBSTAT is here: https://sqlite.org/dbstat.html

Related to #573 which documents Debian has this flag set already.

@pawurb Can you please add a small test like the one in https://github.com/sparklemotion/sqlite3-ruby/pull/578/files to exercise the virtual table and prevent regression? The test may fail on some platforms, in which case I'll need the same sort of metadata mentioned in that PR ("is this using the vendored sqlite or a system sqlite?") to conditionally run the test (and I will add that if needed).

[flavorjones]

Rebased and added a commit to skip the test when using system libraries (specifically, if the user links against sqlcipher or mswin/mingw sqlite -- see https://github.com/sparklemotion/sqlite3-ruby/actions/runs/11910233460 for the failing tests).

[pawurb]

thanks for a quick merge! I've started building https://github.com/pawurb/rails-sqlite-extras so it will help a lot

[flavorjones]

😍 that project looks neat! Hoping to ship a release of this today.