feat: Add miniscript key descriptor methods

[ItoroD]

Description

This is the second part of #949. Here I am adding in all the methods that accept pk as parameter for both single key descriptor and multi.

Notes to the reviewers

I have done this in a series of prs to make it easier to review. I looked at this as 2 logical blocks, first is adding methods that take in simple pk as strings (which is now complete with this pr), second will be adding in methods that take in wrapped pk like Miniscript<Pk, Segwitv0>, Miniscript<Pk, Legacy> and the likes

Documentation

• https://docs.rs/miniscript/12.3.5/miniscript/descriptor/enum.Descriptor.html#method.new_pkh

• https://docs.rs/miniscript/12.3.5/miniscript/descriptor/enum.Descriptor.html#method.new_wpkh

• https://docs.rs/miniscript/12.3.5/miniscript/descriptor/enum.Descriptor.html#method.new_sh_wpkh

• https://docs.rs/miniscript/12.3.5/miniscript/descriptor/enum.Descriptor.html#method.new_sh_sortedmulti

• https://docs.rs/miniscript/12.3.5/miniscript/descriptor/enum.Descriptor.html#method.new_sh_wsh_sortedmulti

• bdk_wallet

• bitcoin

• uniffi

• Other:

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing
• I've added a changelog in the next release tracking issue (see example)
• I've linked the relevant upstream docs or specs above

New Features:

• I've added tests for the new feature
• I've added docs for the new feature

[reez]

ACK a9a2cb0

This mirrors pattern we have nicely