[Bug] Support inclusive end time syntax ] in GROUP BY clause IoTDB 2.0.5

首先定位 SQL GROUP BY 子句的入口点以及区间结束边界的处理方式。复现 issue 中的示例，然后验证是否接受闭合的 ]，并确认时间戳恰好等于结束时间的数据会被包含，同时不改变现有的 [start, end) 行为。

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Version

OS: Ubuntu 24.04 LTS
IoTDB: 2.0.5

Describe the bug and provide the minimal reproduce step

Currently, the GROUP BY clause in IoTDB strictly uses the left-closed, right-open [start, end) time interval format. Users often need to include the data point exactly at the end time (e.g., [start, end]), but the current syntax does not support using ] to specify an inclusive end time.

When querying time-series data, it is common to want a precise inclusive range (e.g., from 12:00 to 13:00 inclusive). To achieve this now, users must manually extend the end_time by a small fraction (e.g., +1ms) or by a full time interval unit, which is unintuitive and can lead to errors or off-by-one queries.

What did you expect to see?

Support the standard interval syntax ] to denote an inclusive end time in the GROUP BY clause.

Example:
Allow this syntax:

SELECT count(s1) FROM root.sg.d1 
GROUP BY ([2026-01-27T12:00:00, 2026-01-27T13:00:00], 1m)

What did you see instead?

Current syntex doesn't allow ] for end time. I have to use the below syntex:

SELECT count(s1) FROM root.sg.d1 
GROUP BY ([2026-01-27T12:00:00, 2026-01-27T13:00:00), 1m)

but it excludes the value at 13:00:00

Anything else?

Current Workaround:
Users currently have to modify the timestamp manually:

-- Extended by 1ms to capture the last point
GROUP BY ([2026-01-27T12:00:00, 2026-01-27T13:00:00.001), 1m)

Are you willing to submit a PR?

• I'm willing to submit a PR!