chore: sort completed transactions

[mmrrnn]

Description

Sort transactions in get_completed_transactions response.

Motivation and Context

Current implementation doesn't allow to fetch only part of all transactions(i.e last 10 txs).

How Has This Been Tested?

manually

[github-actions]

Test Results (CI)

    2 files     86 suites   23m 19s ⏱️
1 349 tests 1 349 ✅ 0 💤 0 ❌
2 698 runs  2 698 ✅ 0 💤 0 ❌

Results for commit d06e9fe.

♻️ This comment has been updated with latest results.

[github-actions]

Test Results (Integration tests)

0 tests  ±0   0 ✅ ±0   0s ⏱️ ±0s
0 suites ±0   0 💤 ±0 
0 files   ±0   0 ❌ ±0 

Results for commit d06e9fe. ± Comparison against base commit 16fb40c.

♻️ This comment has been updated with latest results.

[SWvheerden]

I would not do an order here in rust.
I would change it where it gets it from the database and use SQL to to do the order.

Also don't order by timestamp, order by mined_timestamp