use a standalone org in databend cloud to execute perf test

[flaneur2020]

currently we are using a shared databend cloud org in the perf test and the daily tests.

the perf-test warehosue maybe interleaved with our manual operations, and get the following logs.

2022/07/08 05:48:10 webapi.doRequest POST url=https://test.datafusecloud.com/api/v1/orgs/orgchasen-slug-test/tenant/warehouses req={"imageTag":"v0.7.121-nightly","name":"query-perf","size":"***"} resp={"success":true}
[20](https://github.com/datafuselabs/databend-perf/runs/7246282653?check_suite_focus=true#step:6:21)22/07/08 05:48:10 org: orgchasen-slug-test warehouse status: &framework.WarehouseStatusDTO{Name:"query-perf", ReadyInstances:0, Size:"***", State:"Started", TotalInstances:1}
2022/07/08 05:48:11 org: orgchasen-slug-test warehouse status: &framework.WarehouseStatusDTO{Name:"query-perf", ReadyInstances:0, Size:"***", State:"Started", TotalInstances:1}
20[22](https://github.com/datafuselabs/databend-perf/runs/7246282653?check_suite_focus=true#step:6:23)/07/08 05:48:13 org: orgchasen-slug-test warehouse status: &framework.WarehouseStatusDTO{Name:"query-perf", ReadyInstances:0, Size:"***", State:"Started", TotalInstances:1}
2022/07/08 05:48:17 org: orgchasen-slug-test warehouse status: &framework.WarehouseStatusDTO{Name:"query-perf", ReadyInstances:0, Size:"***", State:"Started", TotalInstances:1}
2022/07/08 05:48:25 org: orgchasen-slug-test warehouse status: &framework.WarehouseStatusDTO{Name:"query-perf", ReadyInstances:0, Size:"***", State:"Started", TotalInstances:1}
2022/07/08 05:48:42 org: orgchasen-slug-test warehouse status: &framework.WarehouseStatusDTO{Name:"query-perf", ReadyInstances:0, Size:"***", State:"Started", TotalInstances:1}
2022/07/08 05:49:14 org: orgchasen-slug-test warehouse status: &framework.WarehouseStatusDTO{Name:"query-perf", ReadyInstances:0, Size:"***", State:"Started", TotalInstances:1}
2022/07/08 05:50:18 org: orgchasen-slug-test warehouse status: &framework.WarehouseStatusDTO{Name:"query-perf", ReadyInstances:0, Size:"***", State:"Suspended", TotalInstances:1}
2022/07/08 05:52:[26](https://github.com/datafuselabs/databend-perf/runs/7246282653?check_suite_focus=true#step:6:27) org: orgchasen-slug-test warehouse status: &framework.WarehouseStatusDTO{Name:"query-perf", ReadyInstances:0, Size:"***", State:"Suspended", TotalInstances:1}
2022/07/08 05:56:43 org: orgchasen-slug-test warehouse status: &framework.WarehouseStatusDTO{Name:"query-perf", ReadyInstances:0, Size:"***", State:"Suspended", TotalInstances:1}
2022/07/08 05:56:43 Error creating warehouse: All attempts fail:

it'd better to make a standalone tenant to seperate the perf-test warehouse.