AbstractBuildForm.php: Implement HTML Formelement attribute 'autofocus'. Add function checkAutoFocus().

Constants.php: Added SQL_LOG_MODE_ERROR - used to force logging of failed SQL queries.
Database.php: Removed temorary debugSql output in error messages. Added 'forced' logging of SQL queries if they failed.

QuickFormQuery.php: Suppress renderinf of form title during a 'delete' call. No one will see and required parameters are not supplied.

AbstractBuildForm.php, BuildFormBootstrap.php, BuildFormTable.php, Constants.php, QuickFormQuery.php, Index.rst: Implemented Paramater 'extraDeleteForm' for 'forms' and 'subrecords'. Doku update.

AbstractBuildForm.php, BuildFormBootstrap.php, BuildFormTable.php: Remove parameter 'table' from Delete SIP URLs. ToolTip updated.

Partially fixes https://project.math.uzh.ch/issues/3066: Once the hidden class has been remove in order to display the validation message, it won't be re-added upon validation success.

QuickFormQuery.php: for modeForm='Form Delete' the 'required param' are not respected - this makes sense, cause these parameters typically filled in newly created records.

Link.php, Report.php: New '_link' token 'x'. '_paged' and '_Paged' are rendered via Link() class, Link() class now supports delete links.

ReportTest.php: implemented various exception tests for missing parameter of _paged

Link.php: Check paged / Paged that the parameter r, table and form are given in the right combination.

ReportTest.php: adjusted test to removed 'p:' parameter

Report.php, Constants.php: introduce constants for report column keywords. Remove code to handle unecessary 'p:' tag for delete links.

Link.php, Report.php, AbstractBuildForm.php, BuildFormBootstrap.php, Constants.php: on various points replaced native string against API_DIR and newly API_DELETE_PHP.

Index.rst, Constants.php: reverted parameter '_table' in delete links back to 'table' - Reason: 'form' needs to be 'form' (instead of '_form') due to many used places already.
Sip.php: move SIP_TARGET_URL back to stored inside SIP - it's necessary for 'delete'-links.