Reduce nested objects in JSON dump

To reduce the dump size, this commit moves the properties of the
following nested objects to their parents:
- tag_type
- type_info
- template_info
- vtable_layout

Bug: 112877706
Test: ./test.py
Change-Id: Ia6e126dbaf85c29eff59f873b4b468bd7a20396a
8 files changed