Close #20315 (fix the panic when parsing invalid input), Speed up #20231 (use ls-tree without size field)
Introduce ListEntriesRecursiveFast (ls-tree without size) and ListEntriesRecursiveWithSize (ls-tree with size)
* Reduce calls to git cat-file -s
There are multiple places where there are repeated calls to git cat-file
-s due to the blobs not being created with their size.
Through judicious use of git ls-tree -l and slight adjustments to the
indexer code we can avoid a lot of these calls.
* simplify by always expecting the long format
* Also always set the sized field and tell the indexer the update is sized
