V3.4.2: Security fixes

Added

• Advertise the 11LTS crowdfunding campaign (#1338, #1346)

Changed

• Improve the type annotations (#1294, #1298, #1357, #1361)
• Move more legacy tests to the new testing framework (#1290, #1356)
• Require oelib >= 3.6.4 (#1353)
• Switch the TER release to Tailor (#1222)

Fixed

• Fix SQL injection in EventBagBuilder::limitToOrganizers (#1322, #1364)
• Fix SQL injection in EventBagBuilder::limitToCategories (#1321, #1362)
• Harden some queries (#1297, #1360)
• Use intExplode where applicable (#1296, #1359)
• Require typo3/class-alias-loader >= 1.1.0 for development (#1245, #1351)
• Keep development-only files out of the TER releases (#1241, #1348)
• Create mkforms-related directories on the fly (#1211)