Allow using a different xtensa toolchain name

[SergioGasquez]

• Updates the IDE configs to use the proper Xtensa toolchain name
• Updates the Rust check to use the proper Xtensa toolchain name

[bugadani]

We also mention a "stable" in template/.github/workflows/rust_ci.yaml, not sure what we should do about that.

[SergioGasquez]

We also mention a "stable" in template/.github/workflows/rust_ci.yaml, not sure what we should do about that.

Yeah, I saw it but I was not sure what to do with it, IMHO its good enough as it is although we might end up using a different toolchain in CI

Edit: Thinking about it again, I guess we wont use a different toolchain in CI, since we have rust-toolchain.toml it would download and use the rigth one.

Edit 2: What could happen (with Xtensa Rust) is that the version the user has locally installed and latest are not the same and in CI we dont specify the version

[MabezDev]

Thanks!