readelf: display dynamic symtab without section headers

readelf: display dynamic symtab without section headers

This commit adds a new option "-D/--use-dynamic" to support printing the
dynamic symbol table from the PT_DYNAMIC segment. By using the
PT_DYNAMIC segment, eu-readelf can go through the contents of dynamic
section entries and the values of each tag. From that, we can get the
address and size of the dynamic symbol table, the address of the string
table, etc.

By using the new option "-D/--use-dynamic", eu-readelf can list the
symbols without section headers.

Example:
  $ ./src/readelf -Ds a.out
      0: 0000000000000000      0 NOTYPE  LOCAL  DEFAULT    UNDEF
      1: 0000000000000000      0 FUNC    GLOBAL DEFAULT    UNDEF __libc_start_main@GLIBC_2.34 (2)
      2: 0000000000000000      0 NOTYPE  WEAK   DEFAULT    UNDEF __gmon_start__

https://sourceware.org/bugzilla/show_bug.cgi?id=28873

Signed-off-by: Di Chen <dichen@redhat.com>