[DWARFLinker][NFC] Change interface of DWARFLinker to specify accel table kinds explicitly.
Currently, DWARFLinker receives kind of accel tables as predefined sets:
```
Apple, ///< .apple_names, .apple_namespaces, .apple_types, .apple_objc.
Dwarf, ///< DWARF v5 .debug_names.
Default, ///< Dwarf for DWARF5 or later, Apple otherwise.
Pub, ///< .debug_pubnames, .debug_pubtypes
```
This patch removes implicit sets of tables(Default, Dwarf) and allows to ask for several sets:
```
Apple, ///< .apple_names, .apple_namespaces, .apple_types, .apple_objc.
Pub, ///< .debug_pubnames, .debug_pubtypes
DebugNames ///< .debug_names.
```
It allows seamlessness adding more accel tables in the future: .gdb_index, .debug_cu_index...
Doing things that way, DWARFLinker will be independent of consumers' requirements.
f.e. dsymutil and llvm-dwarfutil may have different variants for Default set
(so, instead of implementing these differencies inside DWARFLinker it could be
implemented in the corresponding module).
Differential Revision: https://reviews.llvm.org/D132371