feat: Improve accounts list

The accounts lists are now shown per source and/or destination, and
include the name. Furthermore they are sorted alphabetically by name,
because that is how humans think.

README.md

@@ -46,6 +46,8 @@ cargo run -p banks2ff -- destinations
 
 # Inspect accounts
 cargo run -p banks2ff -- accounts list
+cargo run -p banks2ff -- accounts list gocardless  # Only GoCardless accounts
+cargo run -p banks2ff -- accounts list firefly     # Only Firefly III accounts
 cargo run -p banks2ff -- accounts status
 
 # Manage account links
@@ -64,7 +66,7 @@ Banks2FF uses a structured command-line interface with the following commands:
 - `sync <SOURCE> <DESTINATION>` - Synchronize transactions between source and destination
 - `sources` - List all available source types
 - `destinations` - List all available destination types
-- `accounts list` - List all discovered accounts
+- `accounts list [gocardless|firefly]` - List all discovered accounts (optionally filter by adapter type)
 - `accounts status` - Show sync status for all accounts
 - `accounts link` - Manage account links between sources and destinations
 - `transactions list <account_id>` - Show transaction information for a specific account