v1: Track the term of each entry in the log

[freeekanayaka]

Add a data structure that efficiently tracks the term of all entries in the log. It will be used to replace the in-memory cache of the actual log data. Consumers will then be able to choose whether to store the actual log data in memory or on disk.

[codecov[bot]]

Codecov Report

Attention: 82 lines in your changes are missing coverage. Please review.

Comparison is base (7c27391) 72.23% compared to head (31557d2) 73.59%.

:exclamation: Current head 31557d2 differs from pull request most recent head e01b9b4. Consider uploading reports for the commit e01b9b4 to get more accurate results

Files	Patch %	Lines
src/legacy.c	40.54%	9 Missing and 13 partials :warning:
src/trail.c	92.15%	5 Missing and 11 partials :warning:
src/replication.c	65.71%	4 Missing and 8 partials :warning:
src/raft.c	73.33%	1 Missing and 7 partials :warning:
src/restore.c	46.66%	3 Missing and 5 partials :warning:
src/client.c	42.85%	2 Missing and 2 partials :warning:
src/membership.c	57.14%	1 Missing and 2 partials :warning:
src/recv_timeout_now.c	0.00%	0 Missing and 2 partials :warning:
src/uv.c	66.66%	1 Missing and 1 partial :warning:
src/convert.c	50.00%	0 Missing and 1 partial :warning:
... and 4 more

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #139 +/- ## ========================================== + Coverage 72.23% 73.59% +1.35% ========================================== Files 51 52 +1 Lines 9710 10031 +321 Branches 2373 2452 +79 ========================================== + Hits 7014 7382 +368 + Misses 1355 1284 -71 - Partials 1341 1365 +24 ```

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