fix(editor): Fix Multi option parameter expression when the value is an array

[ShireenMissi]

Summary

In multi option parameters, the array is an acceptable value for expressions
This PR:

• Fixes a regression where the expression was converted to a string causing the FE validation to fail and reject arrays
• Fixes a bug when switching from fixed to expression, the value was surrounded by {{}} which made the expression invalid.

Related Linear tickets, Github issues, and Community forum posts

https://linear.app/n8n/issue/NODE-1535/multi-options-component-dont-show-error-when-using-array-in-expression

Review / Merge checklist

• PR title and summary are descriptive. (conventions)
• Docs updated or follow-up ticket created.
• Tests included.
• PR Labeled with release/backport (if the PR is an urgent fix that needs to be backported)

[codecov]

Codecov Report

Attention: Patch coverage is 62.50000% with 3 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...ckages/editor-ui/src/components/ParameterInput.vue	0.00%	3 Missing ⚠️

📢 Thoughts on this report? Let us know!

[michael-radency]

@ShireenMissi I would say this change should be scoped to multi-options input, now it would affect all inputs, that could cause some regressions

[github-actions]

⚠️ Some Cypress E2E specs are failing, please fix them before merging

[cypress]

n8n    Run #8565

Run Properties:   Failed #8565  •  4d4dbaa445: 🌳 🖥️ browsers:node18.12.0-chrome107 🤖 ShireenMissi 🗃️ e2e/*

Project	n8n
Branch Review	node-1535-multi-options-component-dont-show-error-when-using-array-in-expression
Run status	Failed #8565
Run duration	04m 37s
Commit	4d4dbaa445: 🌳 🖥️ browsers:node18.12.0-chrome107 🤖 ShireenMissi 🗃️ e2e/*
Committer	Shireen Missi
View all properties for this run ↗︎

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Test results
Failures	3
Flaky	1
Pending	0
Skipped	0
Passing	355
View all changes introduced in this branch ↗︎

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Tests for review

  14-mapping.cy.ts • 2 failed tests

View Output Video

Test		Artifacts
Data mapping > maps expressions from table header		Test Replay Screenshots Video
Data mapping > maps expressions from json view		Test Replay Screenshots Video

  45-workflow-selector-parameter.cy.ts • 1 failed test

View Output Video

Test		Artifacts
Workflow Selector Parameter > should render add resource option and redirect to the correct route when clicked		Test Replay Screenshots Video

  26-resource-locator.cy.ts • 0 failed tests

View Output

Test		Artifacts

  25-stickies.cy.ts • 0 failed tests

View Output

Test		Artifacts

  233-AI-switch-to-logs-on-error.cy.ts • 0 failed tests

View Output

Test		Artifacts

The first 5 failed specs are shown, see all 42 specs in Cypress Cloud.

  e2e/19-execution.cy.ts • 1 flaky test

View Output Video

Test		Artifacts
Execution > connections should be colored differently for pinned data > when executing a node		Test Replay Screenshots Video