Resolve "Implement stubs for ADMIRE RPCs"

This MR implements basic stubs for the ADMIRE API RPCs for implementation purposes.

Closes #1

See merge request !1

Resolve "Use `file_options` and `genopts` to define the configuration file"

Closes #8

See merge request !6

Resolve "Automatize MARGO_REGISTER"

Closes #5

See merge request !5

Resolve "Support for input/output parameters in RPCs"

Closes #2

See merge request !4

Resolve "Support CI/CMAKE testing"

Closes #3

See merge request !3

Docker image

Solves #4 

The image contains all the dependencies and environment needed to compile scord and run their examples.

See merge request !2