[Release] Prepare for release 0.15

[morningman]

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Description

Hi All:

One quarter has passed since the last release (0.14), and we will start the release of version 0.15.

The release work is roughly divided into the following steps:

1. Create a 0.15 branch and test it
2. Organize release note
3. Release the version according to the release process[1]

I have created the branch-0.15[2]. This branch is currently aligned with the master branch of commit fee8e6a.
This branch will continue to merge some necessary features and bug fixes according to the test situation.

If anyone have a feature that hope to release together in version 0.15, but the PR has not yet been merged, please reply to this email and inform the specific PR.

Any questions are welcome to discuss!

[1] http://doris.incubator.apache.org/master/zh-CN/community/release-process.html
[2] https://github.com/apache/incubator-doris/tree/branch-0.15

Use case

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Related issues

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Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[morningman]

To be merged:

#6667 merged
#6699 merged
#6702 merged
#6644 merged
#6662 merged
#6729 merged

#6650 Hi @caiconghui , as we discuss, this will be merged in next release

[xy720]

Here is my pr needs to be reviewed and merged:
#6705 merged
#6466 merged
#6756 merged
#6859 merged
#6889

[Henry2SS]

Here is a PR needs to be reviewed and merged:
#6554 merged

[morningman]

#6708 merged
#6695 merged

[hf200012]

Here is a PR needs to be reviewed and merged:
#6740 merged

[morningman]

#6768 merged
#6788 merged
#6727 merged
#6795 merged
#6793 merged
#6805 merged
#6766 merged
#6816 merged
#6807 merged

[morningman]

#6836
#6839
#6829
#6826
#6814