[ENH] Add rust message id conversion for pulsar (#1531)

## Description of changes

*Summarize the changes made by this PR.*
 - Improvements & Bug fixes
	 - Adds a pulsar MsgID to our SeqID conversion based on the python version. I think we may need to revisit this encoding, as it reduces the range of the various fields, unless I am thinking about it incorrectly. For now I duplicated what we had, and we can revisit in the future.
 - New functionality
	 - /

## Test plan
*How are these changes tested?*

- [x] Tests pass locally with `cargo test`

## Documentation Changes
*Are all docstrings for user-facing APIs updated if required? Do we need to make documentation changes in the [docs repository](https://github.com/chroma-core/docs)?*

rust/worker/src/ingest/message_id.rs

@@ -0,0 +1,27 @@
+// mirrors chromadb/utils/messageid.py
+use num_bigint::BigInt;
+use pulsar::proto::MessageIdData;
+
+use crate::types::SeqId;
+
+pub(crate) fn pulsar_to_int(message_id: &MessageIdData) -> SeqId {
+    let ledger_id = message_id.ledger_id;
+    let entry_id = message_id.entry_id;
+    let batch_index = message_id.batch_index.unwrap_or(0);
+    let partition = message_id.partition.unwrap_or(0);
+
+    let mut ledger_id = BigInt::from(ledger_id);
+    let mut entry_id = BigInt::from(entry_id);
+    let mut batch_index = BigInt::from(batch_index);
+    let mut partition = BigInt::from(partition);
+
+    // Convert to offset binary encoding to preserve ordering semantics when encoded
+    // see https://en.wikipedia.org/wiki/Offset_binary
+    ledger_id = ledger_id + BigInt::from(2).pow(63);
+    entry_id = entry_id + BigInt::from(2).pow(63);
+    batch_index = batch_index + BigInt::from(2).pow(31);
+    partition = partition + BigInt::from(2).pow(31);
+
+    let res = ledger_id << 128 | entry_id << 96 | batch_index << 64 | partition;
+    res
+}

rust/worker/src/ingest/mod.rs

@@ -1,5 +1,6 @@
 pub(crate) mod config;
 mod ingest;
+mod message_id;
 
 // Re-export the ingest provider for use in the worker
 pub(crate) use ingest::*;