test-compress: add test for short decompress_startswith calls
    
    I thought this might fail with lz4 < 1.8.3, but it seems that because of
    greedy_realloc, we always use a buffer that is large enough, and it always
    passes.
    
    (cherry picked from commit ba17efce44e6a1e139c1671205e9a6ed3824af1b)
    Resolves: #1843871
    
    patch_name: 0386-test-compress-add-test-for-short-decompress_startswi.patch
    present_in_specfile: true
    location_in_specfile: 386
    squash_commits: true