fix(dashboards): Coerce numeric tag values to strings in global filter

[sentry]

This PR addresses the issue "Error: Dashboard filter addOption received a non-string value" (JAVASCRIPT-3BHX).

Problem:
The addOption function in filterSelector.tsx was receiving non-string values, leading to an error being captured by Sentry. This occurred because certain tag values returned by the API (e.g., GoSdkVersion integers, user.geo.subregion codes) were numeric, despite being typed as string in TagValueWithCount.value.

Root Cause:
The existing type guard typeof value === 'string' ? value : value.value in the fetchedFilterValues loop failed to properly coerce these numeric values to strings. When value.value was a number, it was passed directly to addOption, which expected a string. The addOption function itself had a Sentry error capture for non-string inputs, but this only logged the issue without preventing the underlying problem.

Solution:

1. Updated addOption: The addOption function now explicitly coerces rawValue to a string if it's a number or boolean. Other non-string, non-numeric, non-boolean types (like objects) will result in an empty string, preventing [object Object] from appearing.
2. Fixed fetchedFilterValues loop: The type guard in the fetchedFilterValues.forEach loop now explicitly calls String(value.value ?? '') to ensure numeric values from TagValueWithCount are correctly converted to strings.
3. Removed Sentry error capture: The Sentry.withScope block and the Sentry import were removed as the values are now correctly handled, making the error capture redundant.
4. Addressed ESLint warnings: Removed globalFilter.tag.key from the useMemo dependency array as it was no longer needed after removing the Sentry error capture, and refined the rawValue coercion logic to satisfy @typescript-eslint/no-base-to-string.

This ensures that all tag values are consistently handled as strings within the dashboard global filter selector, preventing runtime type errors and improving data consistency.

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Fixes JAVASCRIPT-3BHX

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