Improving ql.ConstNotionalCrossCurrencyBasisSwapRateHelper and ql.MtMCrossCurrencyBasisSwapRateHelper

[QuantAnalyst89]

Improving the ql.ConstNotionalCrossCurrencyBasisSwapRateHelper and ql.MtMCrossCurrencyBasisSwapRateHelper by adding a constructor that takes an overnight index and payment frequency as parameters.

The current helpers have parameters in the link below:

https://rkapl123.github.io/QLAnnotatedSource/df/d10/crosscurrencyratehelpers_8cpp_source.html

[boring-cyborg]

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