* op-batcher: adjust error handling on pending-channels after close

* op-batcher: fix comment

* Capitalize start of log messages
Co-authored-by: Adrian Sutton <adrian@oplabs.co>

* op-batcher: Add NonCompressor for testing purposes

* op-node/rollup/derive: Return ErrChannelOutAlreadyClosed in SpanChannelOut

* op-batcher: Add back outputFrames call to channelManager.Close

Test added that validates that in rare circumstances this is needed.
This happens in scenarios where a block is written to the compressor,
but not flushed yet to the output buffer. If we don't call outputFrames
in channelManager.Close, this test fails.

* op-batcher: Improve logging

- clarify that pending channels will be submitted
- use same key "id" for channel ids everywhere

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Co-authored-by: Sebastian Stammler <seb@oplabs.co>
Co-authored-by: Adrian Sutton <adrian@oplabs.co>