Merge release/2.18.0 to main (#111)

* fix: Check for None type custom dict (#106)

fix: Check for None type custom dict

* Add DNT and custom translation support in NMT client (#108)

* changes made for custom translation, dnt phrases

* formatted

* minor fixes done

* changes made

* minor fix done

* changes done

* changes made

* changes made for dnt and custom translation

* .gitmodules changed

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Co-authored-by: Manisha Johnson <manishaj@nvidia.com>

* fix: undeclared variable (#109)

* Updating git SHA to point to TOT main

* Updating git SHA to point to TOT main

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Co-authored-by: mohnishparmar <109233781+mohnishparmar@users.noreply.github.com>
Co-authored-by: ydharavath <ydharavath@nvidia.com>
Co-authored-by: Manisha Johnson <manishaj@nvidia.com>