Remove all dependencies on exp-verbs

[pakmarkthub]

This change:

• addresses issue get rid of _exp_ types in core.h #79.
• removes exp-verbs and replaces with directverbs.
• enables libgdsync to be compatible with ib-verbs (non-exp) from the perspective of users.
• fixes issue Code style violation #83.
• aligns code in all files.
• fixes issue gds_prepare_send should support all types of opcode #88 and gds_prepare_send should support all types of send_flags #89.

Presubmit Testings:

• gc11 and PSG Cluster
• Tests: gds_kernel_latency, gds_kernel_loopback_latency

[pakmarkthub]

I should have fixed/addressed almost all the comments.

@drossetti Please re-review.

[pakmarkthub]

@drossetti
I made post_send support all types of QP, IBV_WR_*, and IBV_SEND_*. Please take a look if you have time.