Fix missing submit messages for Form

[Soare-Robert-Daniel]

Closes #1804

Summary

Added missing submit messages handlers.

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Test instructions

1. Create a Form and set custom submit messages for Succes and Error in block Inspector.
2. Test the success message.
3. Try to break the form to get the error message.

ℹ️ If you do not want to go through the process of installing the SMPT for mail. You can activate otter pro and use save in Database to test the success message, then switch to Email for error. (You will get an error if you do not have the SMPT set up)

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Checklist before the final review

• Included E2E or unit tests for the changes in this PR.
• Visual elements are not affected by independent changes.
• It is at least compatible with the minimum WordPress version.
• It loads additional script in frontend only if it is required.
• Does not impact the Core Web Vitals.
• In case of deprecation, old blocks are safely migrated.
• It is usable in Widgets and FSE.
• Copy/Paste is working if the attributes are modified.
• PR is following the best practices

[pirate-bot]

Bundle Size Diff

Package	Old Size	New Size	Diff
Animations	270.78 KB	270.78 KB	0 B (0.00%)
Blocks	1.41 MB	1.41 MB	76 B (0.01%)
CSS	85.28 KB	85.28 KB	0 B (0.00%)
Dashboard	122.49 KB	122.49 KB	0 B (0.00%)
Export Import	83.17 KB	83.17 KB	0 B (0.00%)
Pro	302.52 KB	302.52 KB	0 B (0.00%)

[pirate-bot]

Plugin build for 7dc8e53 is ready 🛎️!

• Download Otter – Page Builder Blocks & Extensions for Gutenberg - Production ~ Development
• Download Otter Pro - Production ~ Development
• Download Blocks Animation - Production ~ Development
• Download Blocks CSS - Production ~ Development
• Download Blocks Export Import - Production ~ Development

[pirate-bot]

E2E Summary

Typing

Test	Average Time (ms)	Standard Deviation (ms)	Median Time (ms)	Quantile for soft limit (%)	Quantile for hard limit (%)
Typing	63.64	6.89	61.98	31.58 (60ms)	94.74 (80ms)

Values above 60ms

"0 - 69.79, 3 - 63.00, 5 - 63.45, 7 - 83.62, 8 - 72.55, 9 - 61.98, 10 - 62.55, 13 - 61.11, 14 - 60.93, 15 - 69.42, 16 - 61.41, 17 - 68.43, 18 - 67.43"

[irinelenache]

@Soare-Robert-Daniel Tested and the issue is fixed now 🚀

[pirate-bot]

🎉 This PR is included in version 2.3.4 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀