Allow multiple find_package(SOCI) calls in application using SOCI

Use new SQLite target name for newer CMake versions

Remove rowset_iterator post-increment operator

Update actions/checkout version to 5 in GitHub CI workflows

Always use bundled fmt as header-only library

Merge branch 'fix-values-indicator-use' of github.com:Innokentiy-Alaytsev/soci

Merge branch 'cxx20'

Fixed propagation of NULL indicators in the soci::values::set() function

Added tests for indicator processing by soci::values

Get rid of soci/fmt.h hack

Initialize soci_error::info_ in its declaration

Use C++20 for one of the CI builds

Fix compilation of soci::format() with C++20

Use existing fmt::fmt target if it's already defined

Add SOCI_INSTALL to allow disabling install-related stuff in CMake