add Deref() and GetValue() funcs

[Dentrax]

Signed-off-by: Furkan furkan.turkal@trendyol.com

I tried to use pointer package first time, but unfortunately it couldn't cover my needs for the generics in the first place. So, this PR introduces 2 new functions for generics:

• Deref(): Like Get() but slightly different. It returns any. Which we can nil-check.
• GetValue(): Like the functions in value.go, but using generics to deref under the hood. Only supports primitive types.
• Also updates go.mod to 1.19.

Thanks to @peterhellberg for being helpful on Go Slack! Find his demo: https://go.dev/play/p/bAwvt92thoS

/cc @AlekSi