Add Has Method for OrderedMap

[busi-reddy-karnati]

This pull request introduces a new Has method to the OrderedMap structure across versions and adds corresponding tests and benchmarks to ensure its functionality and performance.

Usage:

for v1

m := orderedMap.NewOrderedMap()
keyExists := m.Has(key)

for v2, v3

m := orderedMap.NewOrderedMap[string, string]()
keyExists := m.Has(key)

Tests:

Added tests for v1, v2, and v3

Benchmarks:

Added benchmarks in v1, v2, and v3

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This change is 

[busi-reddy-karnati]

@elliotchance Sorry about the previously raised PR.
I re-did it!

[elliotchance]

Thanks! I've pushed out the new versions.