[KYUUBI #6867] Refactor the grafana dashboard template

### Why are the changes needed?

The original dashboard dashboard template does not work for my use case:

In this PR:
1. I add the `baseFilter` variable, default value is `job=~"kyuubi"`.
2. apply the `baseFilter` for all expressions
3. add `baseLegend` for the legendFormat
4. Fix hardcode typos
5. remove the `sum` from the expressions for JVM

### How was this patch tested?

<img width="1723" alt="image" src="https://github.com/user-attachments/assets/2da3366d-4cd7-41fe-9a6b-1159d0b61734" />

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes #6867 from turboFei/dash_board.

Closes #6867

d0d1a36 [Wang, Fei] comments
9fc3b5c [Wang, Fei] use kyuubi_jvm_uptime to get instance
280f97c [Wang, Fei] green
f8fc351 [Wang, Fei] all filter
8d1ac2f [Wang, Fei] base legend
9c18bfc [Wang, Fei] save
1a47990 [Wang, Fei] job=kyuubi
ea76345 [Wang, Fei] instant datasource and remove cluster
19db2b3 [Wang, Fei] add filter

Authored-by: Wang, Fei <[email protected]>
Signed-off-by: Cheng Pan <[email protected]>