[Weights] Add last access concept

[Weights] Add last access concept

As all weights are shared now, we need last accesss to be deteremined
This patch implements such behavior with a test

**Self evaluation:**
1. Build test: [X]Passed [ ]Failed [ ]Skipped
2. Run test: [X]Passed [ ]Failed [ ]Skipped

Signed-off-by: Jihoon Lee <jhoon.it.lee@samsung.com>