add solana explorer subtreams

solana-explorer/src/map_block_meta.rs

@@ -0,0 +1,11 @@
+use substreams_solana::pb::sf::solana::r#type::v1::Block;
+use crate::pb::sol::block_meta::v1::BlockMeta;
+
+#[substreams::handlers::map]
+fn map_block_meta(blk: Block) -> Result<BlockMeta, substreams::errors::Error> {
+    Ok(BlockMeta {
+        slot: blk.slot,
+        hash: blk.blockhash,
+        parent_hash: blk.previous_blockhash,
+    })
+}