[Feature Request]: add show active txn statement

[daviszhen]

Is there an existing issue for the same feature request?

• I have checked the existing issues.

Is your feature request related to a problem?

#10948

Describe the feature you'd like

show active txn list all active txns and their stats like user transaction, internal or task, status (blocked by lock, blocked by queue, etc).

Describe implementation you've considered

No response

Documentation, Adoption, Use Case, Migration Strategy

No response

Additional information

suggested by @fengttt , merge the show active txn into the main.

[daviszhen]

• active txns (txnclient.mu.activeTxns)
• user transaction, internal, or task.
• status (blocked by lock(can not be provided not), blocked by queue(waitActiveTxns), etc).

get all txns on all cns:

• rpc to call other cn to get all info

[daviszhen]

draft syntax

show transactions [all] [filter user/not_user/blockedbyqueue/] [order by start_time [desc|asc],...]

all 所有cn；
没有时，当前cn; 

draft result content

columns:
txnId
status
user
start_time ?
duration ?
cn ?

[daviszhen]

关联 #11499

[daviszhen]

关联 #11707 和

[daviszhen]

关联 #11836

[daviszhen]

加好了。