What?

Lodash's trim is used only once in the entire codebase. This PR aims to remove that usage.

Why?

Lodash is known to unnecessarily inflate the bundle size of packages, and in most cases, it can be replaced with native language functionality. See these for more information and rationale:

• Remove lodash dependency from '@wordpress/element' #16938 (comment)
• Remove lodash dependency from WordPress packages. #17025
• @wordpress/api-fetch package has lodash as a dependency #39495

How?

Removing trim is straightforward in favor of a simple String.prototype.trim() replacement. In the cases we need to trim and replace with another character (which our use case is), we use a simple regex replacement. We also use the opportunity to remove a deburr() call as we did in #41687. Finally, we're adding some comments to the regex part for comprehensibility, just like we did in #41687.

Testing Instructions

• Add a Table of Contents block to a post.
• Add a couple of heading blocks with various characters in them
• Verify that the headings appear properly under the Table of Contents block
• Verify that each of the Table of Contents items anchors properly to the corresponding headings.