TTL Heap implementation

[osteensco]

This PR addresses #151.

• refactored NewSugarDB calls in tests to allow for easier config changes.
• added test to Expire in generic module test to check that keys expired as expected.
• added TTLHeap and HeapItem types.
• added necessary methods for TTLHeap to implement the container/heap interface.
• removed eviction sample from sugardb config as it's no longer required.
• made some quality of life adjustments to test_env containers

[osteensco]

Notes:

• This PR still needs to be caught up with main.
• The Test_EvictExpiredTTL in the sugardb Test_Cluster suite is timing out. There are various print statements left in since debugging this is a WIP.
• The root cause of the bug with the above mentioned test has been narrowed down to the follower nodes are receiving the deletion requests from the leader and sending a response back to the leader, but the leader is not receiving this response for some reason.

[osteensco]

FYI, probably gonna hold off and refactor this after #164 gets done.

[osteensco]

I believe I found the root cause to the issue with this PR.
We can observe the deletion requests are sent to all nodes and are successful:

However, from what I understand, a deletion request is also sent to the leader node. I believe this request specifically is what's causing the response to get hung up. This causes a deadlock because in SugarDB.evictKeysWithExpiredTTL() we have to engage the storeLock as well as the keysWithExpiry lock. BUT these two locks are engaged in the HandlerFuncParams.DeleteKey() function.

This seems to be a catch 22, since these locks are needed in both places.