lib: replace remaining use of lucid with blaze for html rendering (#2737)

[acinader]

Closes #2737.

hledger-lib had two renderers for Write.Spreadsheet tables: Write.Html.Lucid (the CLI's -O html) and Write.Html.Blaze (hledger-web's balance page, since #2739). This settles on one, built on blaze-html, see for discussion #2321.

What changed

• Hledger.Write.Html is now the renderer itself: Write.Html.Lucid's cell rendering translated line for line to blaze, plus the Lines class and borderClasses from Write.Html.HtmlCommon. Those two modules and Write.Html.Blaze are deleted.
• balance, register, aregister, print, holdings, and the compound reports (bs/is/cf/bse) import Write.Html; where they wrote lucid markup directly (aregister's heading row, the compound reports' extra styles) they now write blaze markup. hledger-web's balance page only changes an import.
• Dependencies: lucid is dropped from hledger-lib and hledger; hledger gains blaze-html, already a dependency of hledger-lib and hledger-web.
• First unit tests for Write.Html: cell rendering (amount spans, date class, links, totals, borders, colspan/rowspan, escaping), rows, and the styled table.

Output

The CLI's HTML output is byte for byte what it was. I rendered 194 reports with the main build and with this branch and diffed them: balance (single and multi period, --tree, --transpose, --layout bare/tidy/barewide, --budget, -V, -B, --title, --base-url), bs/is/cf/bse, register, aregister (with and without heading), print, and holdings, over examples/sample.journal, examples/multicurrency.journal, a large generated journal, and a journal with multiple commodities, prices, lots, and & < > " ' in account names, descriptions, and the base URL. No differences.

hledger-web's balance now matches CLI's html output: one <span class="amount"> per amount, and a newline after each row. Pages fetched with both builds are otherwise identical.

How to test

stack build --ghc-options=-Werror --test --no-run-tests
stack exec -- hledger test '/Html/'
stack exec -- hledger -f examples/sample.journal bal -M -O html
stack exec -- hledger -f examples/sample.journal is -O html
stack exec -- hledger -f examples/sample.journal areg checking -O html

[simonmichael]

blaze-html hasn't had a release in 2.5 years, which makes me slightly nervous (unlike lucid). But as you say yesod depends on it, so it'll surely keep working.

[simonmichael]

Thanks for the cleanup!