Feature request, adding/extending the default pipeline created by NewPipline for adding more policies

[pfreixes]

Which version of the SDK was used?

v0.14.0

Which platform are you using? (ex: Windows, Linux, Debian)

Linux

What problem was encountered?

There is no an easy way for extending the default policies that are create through azblob.NewPipline which will create an ad-hoc pipeline with the default policies provided by the driver.

If you want to add a new policy, lets say for example for measuring the time spent for making an HTTP call, but you want to still keep using the default policies provided by the driver your are forced to make a copy of this implementation and adding your own policies there.

Ideally you would like to for example an optional parameter with other policies for the azblob.NewPipline function that would be appended to the default ones.

How can we reproduce the problem in the simplest way?

Have you found a mitigation/solution?

We had to copy the function and add our own policy