Fix broken branch switch with similar names

What does this MR do?

Fix the broken URL when switching branches with a similar name from its longer name to its shorter name.

Example:

• development -> dev
• production -> prod

The solution is to ensure an exact match instead of a partial match.

Problem	Fixed
development-to-dev-branch	switching-branch-long-short-name

Testing Case

1. Navigate to a project Repository
2. Repository should have 2 branches with similar names. You can also create these branches.

Example Branches:

• dev
• development

Switch the branch from its longer name to its shorter name and it will work (does not display error flash message).

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

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Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

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• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

Related to #322792 (closed)