move fetch metadata to a separate crate subxt_utils_fetchmetadata (#1829)

* macros: feature-gate jsonrpsee/fetch metadata url

* make CI happy

* Update codegen/src/error.rs

* extract `fetch-metdata` to separate crate

* add missing license headers

* introduce subxt-utils crate

* add missing files

* codegen: remove unused hex crate

* fix test build

* move subxt_utils -> subxt_utils_fetchmetadata

* cargo fmt

* runtime-path -> runtime-metadata-path

* Update utils/fetch-metadata/src/lib.rs

utils/fetch-metadata/Cargo.toml

@@ -0,0 +1,38 @@
+[package]
+name = "subxt-utils-fetchmetadata"
+version.workspace = true
+authors.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+publish = true
+autotests = false
+
+license.workspace = true
+repository.workspace = true
+documentation.workspace = true
+homepage.workspace = true
+description = "subxt utils fetch metadata"
+
+[features]
+url = ["dep:jsonrpsee", "dep:tokio", "dep:url", "frame-metadata"]
+
+[dependencies]
+thiserror = { workspace = true }
+codec = { package = "parity-scale-codec", workspace = true, features = ["derive", "std"] }
+hex = { workspace = true, features = ["std"] }
+
+# Optional dependencies for the `url` feature.
+jsonrpsee = { workspace = true, features = ["ws-client", "http-client"], optional = true }
+tokio = { workspace = true, features = ["rt-multi-thread"], optional = true }
+url = { workspace = true, optional = true }
+frame-metadata = { workspace = true, optional = true, features = ["std"] }
+
+[package.metadata.docs.rs]
+features = ["url"]
+rustdoc-args = ["--cfg", "docsrs"]
+
+[package.metadata.playground]
+default-features = true
+
+[lints]
+workspace = true