Deprecate Pallet decl_* Macros (paritytech#13705)

* Deprecate decl_ macros

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Allow deprecated in tests

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Revert "Allow deprecated in tests"

This reverts commit ce36080.

* Deprecate all

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Push missing files

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* fmt

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Move decl_module to own file

Otherwise i have to spam allow(deprecated) for all recursive calls.

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

* Revert "Move decl_module to own file"

This reverts commit 543a311.

* Fix tests

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

---------

Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>

Author: ggwpez

frame/support/procedural/src/lib.rs

@@ -296,6 +296,8 @@ fn counter_prefix(prefix: &str) -> String {
 /// }
 /// ```
 #[proc_macro]
+#[deprecated(note = "Will be removed soon; use the attribute `#[pallet]` macro instead.
+	For more info, see: <https://github.com/paritytech/substrate/pull/13705>")]
 pub fn decl_storage(input: TokenStream) -> TokenStream {
 	storage::decl_storage_impl(input)
 }

frame/support/src/dispatch.rs

@@ -879,6 +879,8 @@ impl<T> PaysFee<T> for (u64, Pays) {
 ///   in an externalities-provided environment. Implement
 ///   [`IntegrityTest`](./trait.IntegrityTest.html) trait.
 #[macro_export]
+#[deprecated(note = "Will be removed soon; use the attribute `#[pallet]` macro instead.
+	For more info, see: <https://github.com/paritytech/substrate/pull/13705>")]
 macro_rules! decl_module {
 	// Entry point #1.
 	(
@@ -3197,6 +3199,7 @@ macro_rules! __check_reserved_fn_name {
 #[cfg(test)]
 // Do not complain about unused `dispatch` and `dispatch_aux`.
 #[allow(dead_code)]
+#[allow(deprecated)]
 mod tests {
 	use super::*;
 	use crate::{

frame/support/src/error.rs

@@ -67,6 +67,8 @@ pub use sp_runtime::traits::{BadOrigin, LookupError};
 /// For instantiable modules you also need to give the instance generic type and bound to the
 /// error declaration.
 #[macro_export]
+#[deprecated(note = "Will be removed soon; use the attribute `#[pallet]` macro instead.
+	For more info, see: <https://github.com/paritytech/substrate/pull/13705>")]
 macro_rules! decl_error {
 	(
 		$(#[$attr:meta])*

frame/support/src/event.rs

@@ -101,6 +101,8 @@
 /// # fn main() {}
 /// ```
 #[macro_export]
+#[deprecated(note = "Will be removed soon; use the attribute `#[pallet]` macro instead.
+	For more info, see: <https://github.com/paritytech/substrate/pull/13705>")]
 macro_rules! decl_event {
 	(
 		$(#[$attr:meta])*