make scanning pre-carrot and carrot coinbase txs work

src/carrot_core/carrot_enote_types.h

@@ -61,6 +61,8 @@ struct CarrotEnoteV1 final
     crypto::public_key onetime_address;
     /// C_a
     rct::key amount_commitment;
+    /// asset type
+    std::string asset_type;
     /// a_enc
     encrypted_amount_t amount_enc;
     /// anchor_enc
@@ -92,6 +94,8 @@ struct CarrotCoinbaseEnoteV1 final
     crypto::public_key onetime_address;
     /// a
     rct::xmr_amount amount;
+    /// asset type
+    std::string asset_type;
     /// anchor_enc
     encrypted_janus_anchor_t anchor_enc;
     /// view_tag

src/carrot_core/payment_proposal.cpp

@@ -282,8 +282,9 @@ void get_coinbase_output_proposal_v1(const CarrotPaymentProposalV1 &proposal,
         s_sender_receiver,
         output_enote_out.onetime_address);
 
-    // 6. save the amount and block index
+    // 6. save the amount and block index and asset type
     output_enote_out.amount = proposal.amount;
+    output_enote_out.asset_type = proposal.asset_type;
     output_enote_out.block_index = block_index;
 }
 //-------------------------------------------------------------------------------------------------------------------

src/carrot_core/payment_proposal.h

@@ -59,6 +59,8 @@ struct CarrotPaymentProposalV1 final
     CarrotDestinationV1 destination;
     /// b
     rct::xmr_amount amount;
+    /// asset type
+    std::string asset_type;
     /// anchor_norm: secret 16-byte randomness for Janus anchor
     janus_anchor_t randomness;
 };