[neurun] Merge Equal and NotEqual to Comparison op (#4797)

[neurun] Merge Equal and NotEqual to Comparison op (#4797)

In https://github.sec.samsung.net/STAR/nnfw/pull/4738#discussion_r156180, we've discussed to group all operations in `::arm_compute::ComparisonOperation`.
This commit introduces `ComparisonNode` that includes operations in `::::arm_compute::ComparisonOperation` and intergrate `Equal` and `NotEqual` to `ComparisonNode`

`ComparisonNode` can be support below.

```
enum class ComparisonType
 {
   Equal,
   NotEqual,
   Greater,
   GreaterEqual,
   Less,
   LessEqual
 };
```

Signed-off-by: sjsujinkim <sjsujin.kim@samsung.com>