Enable Basic Tests and Use 4 Theads to Build

[DoctorLai]

This is the ninth PR of the DAO Project Proposal: Fixing Steemd Build Dependencies in the Latest OS.

Previous PRs:

• #3706 (CI Pipeline)
• #3705 (Refactor/Fixes)
• #3704 (Fix test_block_log)
• #3703 (Debian13)
• #3702 (AzureLinux3)
• #3701 (Ubuntu24.04)
• #3700 (Ubuntu22.04)
• #3699 (Ubuntu20.04 - cleanup - submodule fixes etc)

Basic Tests

This PR enables the basic tests via BUILD_TESTING and use four threads via NUMBER_BUILD_THREADS