Consider renaming the 'runtime' interface to 'store' for consistency with other WASI proposals

[lukewagner]

Since originally suggesting runtime as the interface name, some naming conventions have emerged elsewhere in WASI, in particular, having the interface names be nouns instead of adjectives. Also, wasi-keyvalue has wasi:keyvalue/store and there's a nice symmetry between that and wasi:config/store.

The original idea of runtime was to distinguish the runtime get lookup from a more declarative interface that allowed a component to statically enumerate the specific configuration values it needed as value imports. However, I think a "store" communicates this just as well and there are plenty of names left for declarative value imports.

[thomastaylor312]

This shouldn't be too hard to do. I do know that at least in wasmCloud we have a bunch of things that use this interface as it is currently, so we might have to do an adapter for this to ease the transition. But I also know we were thinking of cutting the actual 0.2.0 of this soon so probably good to do it now

[Mossaka]

agreed to the rename and agreed that this should be done prior to 0.2.0 cut