A lyrics and chords formatting program

Changes for 6.020 - 2023-07-21

• !ChordPro functionality
• New directive diagrams obsoletes grid/no_grid with more possibilities, Based on a suggestion and concept implementation from Jörg Bublath.
• Images without directory can be looked up in CHORDPO_LIB.
• Turn pseudo-chords like | and spaces into annotations.
• !BugFixes
• Fix a number of problems with define/copy/copyall.
• Fix issue #293.
• !Internal
• Bump minimal perl version to 5.26 and add Object::Pad to dependencies.
• Change namespace App::Music::ChordPro to ChordPro.
• Put VERSION on single line for stupid tools.
• Upgrade ChordPro::Chords::Appearance to class.
• Enhance Parser to use signatures to catch call errors.
• Enhance Config to use signatures to catch call errors.
• Enhance Chords to use signatures to catch call errors.
• Enhance Utils to use signatures to catch call errors.