load the dbghelp in core before all plugins

[psifertex]

We have run into multiple issues with the wrong dbghelp being loaded on windows. We'd like to propose moving it into the core and initializing it there based on the one we ship (when it exists) so that we can avoid these issues in the future. (issue being if the OS-provided one loads first, the debugger will be broken).

[xusheng6]

Yeah this has been a long-standing issue. The proposed change is beneficial and I like the idea

Two related scenarios:

1. EDR/anti-virus might inject the dbghelp.dll before any code execution

2. We might want to swap the version of dbgeng DLLs at time. For example, when doing unit test, we might want to first test regular debugging with dbgeng, then TTD with the downloaded windbg

Both issues are tricky, though it's far-less common than the situation described in this issue

[xusheng6]

Also for context -- this has been really painful to handle, but it's less of a big deal bc the default windows adapter is now the windows native debug adapter, which is not affected by this