CW-608-Fetch-And-Save-Icons-Of-ERC20-And-SPL-Tokens-When-Adding-Them (#1365)

* feat: Fetch and save icons of SPL tokens when adding them

* feat: Implement fetch and save icons for ERC20 tokens when adding them

* fix: Add moralisApiKey to evm secrets

* Add check to ensure decimals cannot be zero

* - Fallback to adding erc20 token from web3dart
- Wrap fetching spl token icon in a try/catch block

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Co-authored-by: OmarHatem <omarh.ismail1@gmail.com>

tool/utils/secret_key.dart

@@ -42,6 +42,7 @@ class SecretKey {
   static final evmChainsSecrets = [
     SecretKey('etherScanApiKey', () => ''),
     SecretKey('polygonScanApiKey', () => ''),
+    SecretKey('moralisApiKey', () => ''),
   ];
 
   static final solanaSecrets = [