Test RPM with corrupted ELF interpreter in separate debuginfo
cxxll::elf_image: Do not report some corrupted ELF interpreters

This part of the code is now in line with readelf from elfutils commit
cb7b2d64b6fdbbb6f18ce07294b2315f60d843bc.
database loading code: Introduce add_elf_program_header()
SQL schema: Add table symboldb.elf_section_header
cxxll::elf_image::section_header_range: New class
database: Load symboldb.elf_section_header table
Test coverage for symboldb.elf_section_header table
Python coverage in the integration test
Remove special Python tests now included in the general integration test
Reorganize Python loading code