btcutil: update to chaincfg/chainhash/v1.1.0

[Roasbeef]

This is a follow up to https://github.com/btcsuite/btcd/pull/1978.

We bump to the new chainhash version, then start to use the functionality where applicable.

Next in the sequence is:

1. Merge this.
2. Update btcutil/psbt.
3. Merge that
4. Update the top-level pacakge (use the two new version above), then merge that.

We'll also want to revisit this PR, as it aims to resolve some of the current module issues that cause PR chains like this each time we update a sub-module: https://github.com/btcsuite/btcd/pull/1825

[coveralls]

Pull Request Test Coverage Report for Build 7227862106

• 0 of 8 (0.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.003%) to 56.073%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
btcutil/gcs/builder/builder.go	0	8	0.0%
<!--	Total:	0	8	0.0%	-->

Totals
Change from base Build 7227596643:	0.003%
Covered Lines:	27982
Relevant Lines:	49903

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💛 - Coveralls