SCIM token should include `oxide-scim-` prefix

[david-crespo]

It's part of the token, so I think it should be included so we don't have to instruct the user to add it.

omicron/nexus/tests/integration_tests/scim.rs

Lines 446 to 450 in 9617f40

	RequestBuilder::new(client, Method::GET, "/scim/v2/Users")
	.header(
	http::header::AUTHORIZATION,
	format!("Bearer oxide-scim-{}", created_token.bearer_token),
	)

This is how we do it with regular access tokens:

omicron/nexus/db-model/src/device_auth.rs

Lines 184 to 193 in 9617f40

	impl From<DeviceAccessToken> for views::DeviceAccessTokenGrant {
	fn from(access_token: DeviceAccessToken) -> Self {
	Self {
	access_token: format!("oxide-token-{}", access_token.token),
	token_type: views::DeviceAccessTokenType::Bearer,
	token_id: access_token.id.into_untyped_uuid(),
	time_expires: access_token.time_expires,
	}
	}
	}

It would be trivial to add for SCIM tokens:

omicron/nexus/db-model/src/scim_client_bearer_token.rs

Lines 44 to 53 in 9617f40

	impl From<ScimClientBearerToken> for views::ScimClientBearerTokenValue {
	fn from(t: ScimClientBearerToken) -> views::ScimClientBearerTokenValue {
	views::ScimClientBearerTokenValue {
	id: t.id,
	time_created: t.time_created,
	time_expires: t.time_expires,
	bearer_token: t.bearer_token,
	}
	}
	}