add a check for non-unique decorator names

[m7pr]

The same as in tmc
insightsengineering/teal.modules.clinical@b048f37
do not allow decorators with duplicated names

[github-actions]

Unit Tests Summary

  1 files   22 suites   13m 1s ⏱️
145 tests 107 ✅ 38 💤 0 ❌
476 runs  438 ✅ 38 💤 0 ❌

Results for commit 18cf80e.

♻️ This comment has been updated with latest results.

[github-actions]

Unit Test Performance Difference

Test Suite	$Status$	Time on main	$±Time$	$±Tests$	$±Skipped$	$±Failures$	$±Errors$
shinytest2-tm_g_scatterplot	💚	$74.21$	$-1.00$	$0$	$0$	$0$	$0$
shinytest2-tm_g_scatterplotmatrix	💔	$27.22$	$+1.22$	$0$	$0$	$0$	$0$
shinytest2-tm_misssing_data	💔	$47.64$	$+1.26$	$0$	$0$	$0$	$0$

Results for commit 17c9c41

♻️ This comment has been updated with latest results.

[llrs-roche]

If there are duplicated decorators and decorators that won't be used by the module only the first issue will be raised.

[m7pr]

@llrs-roche Just sent the same fix as in here