In this PR, several changes have been made:
(a) restructure the trienode history header section
Previously, the offsets of the key and value sections were recorded before
encoding data into these sections. As a result, these offsets referred to the
start position of each chunk rather than the end position.
This caused an issue where the end position of the last chunk was
unknown, making it incompatible with the freezer partial-read APIs.
With this update, all offsets now refer to the end position, and the
start position of the first chunk is always 0.
(b) Enable partial freezer read for trienode data retrieval
The partial freezer read feature is now utilized in trienode data
retrieval, improving efficiency.
The limit check for `MaxUint32` is done after the cast to `int`. On 64
bits machines, that will work without a problem. On 32 bits machines,
that will always fail. The compiler catches it and refuses to build.
Note that this only fixes the compiler build. ~~If the limit is above
`MaxInt32` but strictly below `MaxUint32` then this will fail at runtime
and we have another issue.~~ I checked and this should not happen during
regular execution, although it might happen in tests.
