refactor, txdb: Add CoinsViewOptions struct

Add CoinsViewOptions struct to remove ArgsManager uses from txdb.

To reduce size of this commit, this moves references to gArgs variable out of
txdb.cpp to calling code in validation.cpp. But these moves are temporary. The
gArgs references in validation.cpp are moved out to calling code in init.cpp in
later commits.

This commit does not change behavior.

src/validation.h

@@ -408,7 +408,7 @@ public:
     //! state to disk, which should not be done until the health of the database is verified.
     //!
     //! All arguments forwarded onto CCoinsViewDB.
-    CoinsViews(fs::path ldb_name, size_t cache_size_bytes, bool in_memory, bool should_wipe);
+    CoinsViews(DBParams db_params, CoinsViewOptions options);
 
     //! Initialize the CCoinsViewCache member.
     void InitCache() EXCLUSIVE_LOCKS_REQUIRED(::cs_main);