Feature idea: constant primitive values

[maxburke]

It would be Really Convenient to be able to declare primitive constants (floats, ints, strings) so that these are available in cross-language contexts. Right now my project uses a bunch of janky JSON files that declare our constants and we have a Python script that generates code for them, but it would be great to sunset that and have it all done with flatc, and kept within the same flatbuffer definition file where the associated data types are defined.

For example, I was thinking syntax like:

const SOME_CONSTANT_STRING: string = "hello";
const SOME_CONSTANT_FLOAT: float = 1.0;

Ideas? Thoughts?