Fix wrong color of buttons in dark mode

[Tostti]

Description

This PR fixes a problem where the buttons in the flyout had the incorrect color in dark mode.
To solve this, a style was added for the dark mode in public/styles/theme/dark/index.dark.scss

Issues Resolved

#7158

Evidence

Before

After

Test

• Bring up a Wazuh environment with events or sample data
• Go to Threat hunting, and open the Events tab
• In one of the events, click the button Inspect document details at the left. A flyout should open
• In the flyout, place the cursor above any of the rows. Action buttons should appear at the right. Verify the button colors
• Test for light and dark mode

Check List

• All tests pass
  • yarn test:jest
• New functionality includes testing.
• New functionality has been documented.
• Update CHANGELOG.md
• Commits are signed per the DCO using --signoff

[guidomodarelli]

Legend:
⚫: The test hasn't started yet
🟢: All checks passed.
🟡: There is at least one expected fail or skipped test and no failures.
🔴: There is at least one failed check.
⚪: Doesn't apply

CR 🟢
TEST 🟢

Dark

Light

[github-actions]

Wazuh Core plugin code coverage (Jest) test	%	values
Statements	45.5%	( 400 / 879 )
Branches	41.09%	( 157 / 382 )
Functions	43.87%	( 136 / 310 )
Lines	45.69%	( 398 / 871 )

[github-actions]

Wazuh Check Updates plugin code coverage (Jest) test	%	values
Statements	76.44%	( 172 / 225 )
Branches	58.65%	( 61 / 104 )
Functions	61.7%	( 29 / 47 )
Lines	76.44%	( 172 / 225 )

[github-actions]

Main plugin code coverage (Jest) test	%	values
Statements	14.93%	( 4443 / 29756 )
Branches	9.79%	( 1886 / 19255 )
Functions	14.69%	( 1056 / 7186 )
Lines	15.14%	( 4337 / 28628 )

[JuanGarriuz]

Test

[JuanGarriuz]

LGTM!!