Some code parts use `std::vector::emplace_back(...)` in a non-efficient way.

Instead of passing the arguments for constructing the object in-place, we are passing a temporary object. The temporary object will then be std::moved into the vector by the `emplace_back` call. This can be improved by just passing the arguments to construct the object in-place.

For example, instead of

std::vector<LiteParsedPipeline> liteParsedPipelines;
...
liteParsedPipelines.emplace_back(LiteParsedPipeline(nss, rawPipeline.second));

we could do

std::vector<LiteParsedPipeline> liteParsedPipelines;
...
liteParsedPipelines.emplace_back(nss, rawPipeline.second);

This avoids calling the move ctor in addition to the object creation.

We have this pattern in several places in the code. We should fix the easy-to-identify ones.