Fix iterator not iterating over all chunks

[achim-k]

Public-Facing Changes

Fix iterator not iterating over all chunks

Description

Supersedes #72

In my scenario, starting from {sec: 0, nsec: 0}, when reading topic=['A ',' B '], we first read A1, B1, A2, and then position is at position Other (red line). After the heap is consumed, we call LoadNext (to read chunkB, chunkC) and cannot read the data. We then perform an additional loadNext, but still cannot read the data at chunkC, and then exit. We lost the data for A3.

[linear]

FG-6304 Review community pr rosbag/72