Storage initialization is idempotent (#4543)

## Motivation

Currently, initializing a storage is a one-time only operation meaning
that if we try to do it again it will return an error.

## Proposal

Storage initialization is an idempotent operation – we only write blobs
under specific keys.

Do not return an error, instead return early with `Ok(())`, if storage
is already initialized.

## Test Plan

CI

## Release Plan


- These changes follow the usual release cycle.
- These changes should be backported to the latest `testnet` branch,
then
    - be released in a new SDK
  
## Links

- [reviewer
checklist](https://github.com/linera-io/linera-protocol/blob/main/CONTRIBUTING.md#reviewer-checklist)

Author: deuszx

linera-client/src/config.rs

@@ -30,8 +30,6 @@ pub enum Error {
     Chain(#[from] linera_chain::ChainError),
     #[error("persistence error: {0}")]
     Persistence(Box<dyn std::error::Error + Send + Sync>),
-    #[error("storage is already initialized: {0:?}")]
-    StorageIsAlreadyInitialized(Box<NetworkDescription>),
     #[error("no admin chain configured")]
     NoAdminChain,
 }
@@ -169,15 +167,16 @@ impl GenesisConfig {
             .await
             .map_err(linera_chain::ChainError::from)?
         {
-            return Err(Error::StorageIsAlreadyInitialized(Box::new(description)));
+            tracing::debug!(?description, "storage already initialized");
+            return Ok(());
         }
         let network_description = self.network_description();
         storage
-            .write_blob(&self.committee_blob())
+            .write_network_description(&network_description)
             .await
             .map_err(linera_chain::ChainError::from)?;
         storage
-            .write_network_description(&network_description)
+            .write_blob(&self.committee_blob())
             .await
             .map_err(linera_chain::ChainError::from)?;
         for description in &self.chains {