* adds back position field to coding-shred-header (#21600)
https://github.com/solana-labs/solana/pull/17004
removed position field from coding-shred-header because as it stands the
field is redundant and unused.
However, with the upcoming changes to erasure coding schema this field
will no longer be redundant and needs to be populated.
(cherry picked from commit cd17f63d81
)
# Conflicts:
# core/src/window_service.rs
# ledger/src/blockstore.rs
# ledger/src/shred.rs
* removes backport merge conflicts
Co-authored-by: behzad nouri <behzadnouri@gmail.com>