Compress embedded GDExtension interface

[RedworkDE]

Stops older MSCV compiler versions from failing to build because of the huge string literal and saves about 60kb in the final executable.

Code largely follows that same patterns as make_doc_header and make_certs_header.

[YuriSizov]

So, what prompted this PR is that I reported that I can no longer build master after #76406. I use MSVC 14.2 (builds tools from Visual Studio 2019), and I encountered this issue:

core/extension/gdextension_interface_dump.gen.h(1589): fatal error C1091: compiler limit: string exceeds 65535 bytes in length

I can confirm that with this patch applied my builds can continue past the point of previous error. But I think someone more competent in the area should review and approve the PR, if this is the correct fix.

[dsnopek]

I built and tested godot --dump-gdextension-interface with this PR, and it worked as expected! So, from a GDExtension perspective, this looks good.

Comparing the new code with make_doc_header() in the buildsystem and DocTools::load_compressed() in the engine, it does really look the same.

[YuriSizov]

Approving it then, tentatively :)

[akien-mga]

Thanks!