Optimize country lookup by using a dictionary

[nikola-golijanin]

Optimize country lookup by by using a dictionary for faster access and improve null handling in country retrieval methods

[Clifftech123]

@nikola-golijanin Can you go ahead and implementing that

[nikola-golijanin]

@Clifftech123 I opened a PR with some simple improvements :)

[Clifftech123]

@nikola-golijanin will look into thank you