Give all HTML button elements a type

[timvandermeij]

The HTML button elements we use are all regular buttons that don't submit form data to a server. According to
https://developer.mozilla.org/en-US/docs/Web/HTML/Element/button#notes those buttons should all have their type set to button explicitly, but we only do that a handful of them. This commit fixes the issue by consistently giving all our buttons the button type.

Extracts a part of #18385.

[calixteman]

I discovered this issue thanks to a warning in Edge console.

[timvandermeij]

I have verified that all buttons now have the button type using the following one-liner (the XFA ones originate from the PDF contents and should stay like this):

$ grep -r '<button' * | grep -v 'type="button"'
grep: test/pdfs/xfa_filled_imm1344e.pdf: binary file contains the text
test/unit/xfa_tohtml_spec.js:            <button/>
test/unit/xfa_tohtml_spec.js:            <button/>

This can be compared to master where the command found 60 occurrences instead:

$ grep -r '<button' * | grep -v 'type="button"' | wc -l
60

[timvandermeij]

/botio-linux preview

[moz-tools-bot]

From: Bot.io (Linux m4)

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Received

Command cmd_preview from @timvandermeij received. Current queue size: 0

Live output at: http://54.241.84.105:8877/ab493312e211266/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

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Success

Full output at http://54.241.84.105:8877/ab493312e211266/output.txt

Total script time: 1.21 mins

Published

• Viewer: http://54.241.84.105:8877/ab493312e211266/web/viewer.html
• Viewer (legacy): http://54.241.84.105:8877/ab493312e211266/legacy/web/viewer.html

[timvandermeij]

/botio integrationtest

[moz-tools-bot]

From: Bot.io (Windows)

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Received

Command cmd_integrationtest from @timvandermeij received. Current queue size: 0

Live output at: http://54.193.163.58:8877/957a1d6e95a1158/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

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Received

Command cmd_integrationtest from @timvandermeij received. Current queue size: 0

Live output at: http://54.241.84.105:8877/144226ddc948f48/output.txt

[moz-tools-bot]

From: Bot.io (Linux m4)

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Success

Full output at http://54.241.84.105:8877/144226ddc948f48/output.txt

Total script time: 8.43 mins

• Integration Tests: Passed

[moz-tools-bot]

From: Bot.io (Windows)

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Failed

Full output at http://54.193.163.58:8877/957a1d6e95a1158/output.txt

Total script time: 17.70 mins

• Integration Tests: FAILED