[BUG] The float value percentage of `storage_page_cache_limit` will cause the page_cache capacity calculation result to be wrong

[xinyiZzz]

Describe the bug
For example, when setting storage_page_cache_limit=0.1% in be.conf, the method ParseUtil::parse_mem_spec in ExecEnv::_init_mem_tracker() returns storage cache capacity = -1.

After the parameters are passed to StoragePageCache::create_global_cache, storage cache capacity will be converted from int64_t to size_t and then equal to 18446744073709551615