(feat) Show error message from server when form submission fails

[donaldkibet]

Requirements

• This PR has a title that briefly describes the work done including the ticket number. If there is a ticket, make sure your PR title includes a conventional commit label. See existing PR titles for inspiration.
• My work conforms to the OpenMRS 3.0 Styleguide and design documentation.
• My work includes tests or is validated by existing tests.

Summary

Attempt to extract the exact error message from the server response if the encounter POST request fails when submitting a form.

[github-actions]

Size Change: -3.85 kB (-1%)

Total Size: 543 kB

ℹ️ View Unchanged

Filename	Size	Change
dist/225.js	9.82 kB	0 B
dist/272.js	6.59 kB	0 B
dist/290.js	81.1 kB	0 B
dist/294.js	2.63 kB	0 B
dist/366.js	6.94 kB	0 B
dist/554.js	32.3 kB	-1.93 kB (-6%)	✅
dist/591.js	2.96 kB	0 B
dist/595.js	106 kB	0 B
dist/634.js	777 B	0 B
dist/709.js	2.42 kB	0 B
dist/986.js	193 kB	0 B
dist/main.js	96 kB	-1.92 kB (-2%)
dist/openmrs-form-engine-lib.js	3.25 kB	0 B

_{compressed-size-action}

[denniskigen]

Thanks, Donald!