This regressed in 2b202ce6, which removed `ACTCTX_FLAG_RESOURCE_NAME_VALID`
during `CreateActCtxW` under the assumption that an executable only has
one manifest. conhost has two however and we need to pick the correct one.
On OpenConsole this causes the expected `ERROR_SXS_PROCESS_DEFAULT_ALREADY_SET`.
Closes MSFT:38355907
This commit enables /permissive- for all projects, as well as all other /Zc
flags not enabled by default by /permissive-. Some projects continue to be
built under /Zc:twoPhase- as JsonUtils.h fails to compile otherwise.
## PR Checklist
* [x] Closes#10703
* [x] I work here
* [x] Tests added/passed
