Do not assert page is evicted from back forward cache (#47582)
The test aims to verify that a page with open database connection can enter back
forward cache, and new open database request from an active page does not get
blocked by open connection of cached page. This is the behavior implemented in
Chrome, Firefox and Safari. However, the test also asserts the cached page is
removed from back forward cache. The eviction is unnecessary because request can
be unblocked as long as the connection on cached page is closed. Currently
Chrome and Firefox evict page from cache but Safari does not. Since this
behavior is implementation-defined, we should drop the assertion from the test.
Also, update the tests to use different database names so they don't affect each
other.