fix: Search closes in dropdown when search text contains space

[vicky-primathon]

Description

Fixes #9597

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Test coverage results 🧪

🟢 Total coverage has increased

// Code coverage diff between base branch:release and head branch: fix/dropdown-filter 

Status	File	% Stmts	% Branch	% Funcs	% Lines
🟢	total	55.04 (0.01)	36.38 (0.01)	34.71 (0)	55.42 (0.01)
🟢	app/client/src/components/ads/Dropdown.tsx	82.21 (0.58)	61.85 (0.34)	69.44 (0)	81.03 (0.5)

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[github-actions]

Unable to find test scripts. Please add necessary tests to the PR.

[chandannkumar]

Tested the PR and it is working fine

[vicky-primathon]

/ok-to-test sha=db1700e

[vicky-primathon]

/ok-to-test sha=203fcf7

[github-actions]

Tests running at: https://github.com/appsmithorg/appsmith/actions/runs/1812279527.
Workflow: Appsmith External Integration Test Workflow.
Commit: 203fcf7.
PR: 10945.

[github-actions]

Unable to find test scripts. Please add necessary tests to the PR.