Merge #13264: [qt] Satoshi unit

Summary:
c722f00a7 [qt] Added satoshi unit "Satoshi (sat)" will be displayed in dropdowns and status bars. "sat" will be used when appended to numbers. (GreatSock)
4ddbcbf8c [qt] BitcoinUnits::format with zero decimals Formatting with zero decimals will now result in 123 instead of 123.0 (GreatSock)

Pull request description:

This adds satoshi as an additional amount unit for the GUI.

Tree-SHA512: c166c96c9a434b6ac700e1628e54f2dbb132c5232d949c0b464f61276a91d56f9bab4a62d50780535f1d34eaac6484f693a1e0611cd7c9d1ed5ebee066c0dd08

Backport of Core PR13264

Test Plan:

ninja
./bitcoin-qt

Settings -> Options -> Display -> change units to Satoshi
Verify change in units in display.

Reviewers: O1 Bitcoin ABC, #bitcoin_abc, Fabien

Reviewed By: O1 Bitcoin ABC, #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D5432