feat(sgxGramineContainer): expose maxLayers argument from image builder

[ozwaldorf]

Summary

The current sgxGramineContainer builder uses a lot of layers by itself, not leaving much room for more complex enclaves before hitting a compile time error. Allowing users to adjust the maxLayers parameter is sufficient to solve the issue.

error: builder for '/nix/store/nr78hkr0x4s1rq5xz69yvk3hxgcpqzpy-foobar-manifest-app-conf.json.drv' failed with exit code 1;
       last 1 log lines:
       > Error: usedLayers 101 layers to store 'fromImage' and 'extraCommands', but only maxLayers=100 were allowed. At least 1 layer is required to store contents.

What's changed

• Exposed the maxLayers argument from dockerTools.buildLayeredImage and uses it throughout the builder in each step

[haraldh]

I did the same thing yesterday... 🤣