va-search-input: Resolve Stencil test warning about isTouched re-rendering

[jamigibbs]

Description

There is a Stencil test warning that we should resolve for va-search-input:

A draft PR has been created that removes the @State decorator because it didn't seem like the correct use of @State Every time that variable is set, it's causing a full re-render of the component.

This solution or any alternate solution needs to be tested in vets-website. Specifically, we need to make sure the following issue is still fixed and there hasn't been any other regressions:

• Bug - va-search-input suggestion box doesn't close #2795
• https://dsva.slack.com/archives/C01DBGX4P45/p1714663661141389?thread_ts=1714054912.852109&cid=C01DBGX4P45

Tasks

• resolve the Stencil warning for isTouched
• verify that no regression were introduced in vets-website

Acceptance Criteria

• the isTouched test warning is resolved