Issues-count endpoint does not support the same search syntax as issues

### Environment

SaaS (https://sentry.io/)

### Steps to Reproduce

Going to product details page and entering a search syntax like `foo is bar`, causes the issues table and the counts in the header to be mismatched or fail to load.

There are two underlying issues:
- The query is not forwarded to the count request
- The backend does not support the query

Since the counts request does not forwards the query, we can end up in a state where we have an empty issues table with header values like unresolved (n), where n > 0, but the table remains empty.

I thought that this was a simple fix by just forwarding the query to the counts endpoint, which ended up in a failed request and an error message of `detail: "Invalid value for \"is\" search, valid values are ['ar...`

Originally reported by @Kobby-Bawuah [here](https://sentry.slack.com/archives/CQDHVRS2W/p1729550537834749)

### Expected Result

The table should display the correct counts based on the query
The issue-counts endpoint should support the same syntax as the issues endpoint

### Actual Result

Table is empty, header shows `Unresolved N+` issues along with a count of > 1 for other types

### Product Area

Issues

### Link

_No response_

### DSN

_No response_

### Version

_No response_