[opt](config) add max_bucket_num_per_partition config to limit bucket number

[gavinchou]

Proposed changes

Add a new FE config max_bucket_num_per_partition to limit the maximum number of buckets when creating a table or adding a partition.

Changes:

1. Add max_bucket_num_per_partition config in Config.java, defaulting to autobucket_max_buckets (128) for consistency.
2. Add bucket number validation in DistributionDescriptor.validate() for CREATE TABLE scenario.
3. Add bucket number validation in InternalCatalog.addPartition() for ALTER TABLE ADD PARTITION scenario.
4. Add unit tests for the new validation logic.

Behavior:

• For user-specified buckets (CREATE TABLE / ALTER TABLE ADD PARTITION): if bucket number exceeds this limit, the operation will be rejected with a helpful error message.
• For auto-bucket feature (Dynamic Partition): bucket number is capped by autobucket_max_buckets automatically, no change.
• Set to 0 or negative value to disable this limit.

Error message example:

Number of buckets (200) exceeds the maximum allowed value (128). 
Generally, a large number of buckets is not needed. 
If you have a specific use case requiring more buckets, 
please review your schema design or modify the FE config 
'max_bucket_num_per_partition' to adjust this limit.

Test plan

• Unit tests added in DistributionDescriptorTest.java
• Verify CREATE TABLE with bucket number exceeding limit is rejected
• Verify ALTER TABLE ADD PARTITION with bucket number exceeding limit is rejected
• Verify auto-bucket is not affected by this limit
• Verify setting config to 0 disables the limit

[Thearas]

Thank you for your contribution to Apache Doris.
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Please clearly describe your PR:

1. What problem was fixed (it's best to include specific error reporting information). How it was fixed.
2. Which behaviors were modified. What was the previous behavior, what is it now, why was it modified, and what possible impacts might there be.
3. What features were added. Why was this function added?
4. Which code was refactored and why was this part of the code refactored?
5. Which functions were optimized and what is the difference before and after the optimization?

[gavinchou]

run buildall

[gavinchou]

run compile