feat: implement greptime cli export

[waynexia]

I hereby agree to the terms of the GreptimeDB CLA

What's changed and what's your intention?

implement greptime cli export command line for exporting all SHOW CREATE TABLE under one catalog。

E.g.:

greptime cli export --addr "127.0.0.1:4001" --catalog greptime --schema public --output-dir /tmp/greptimedb-export --target create-table

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.

Refer to a related PR or issue link (optional)

[codecov]

Codecov Report

Merging #2535 (e310361) into develop (825e4be) will decrease coverage by 0.51%.
The diff coverage is 2.39%.

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2535      +/-   ##
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- Coverage    85.34%   84.84%   -0.51%     
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  Files          737      738       +1     
  Lines       117986   118193     +207     
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- Hits        100697   100277     -420     
- Misses       17289    17916     +627     

[sunng87]

How about changing --schema and --catalog to --database for consistency with mysql? So we don't need to explain schema/catalog concept in our docs.

[waynexia]

How about changing --schema and --catalog to --database for consistency with mysql? So we don't need to explain schema/catalog concept in our docs.

--schema and --catalog can be assigned separately, e.g., only export tables under catalog = greptime. Does --database has the same semantic?

[sunng87]

In that case we will need to support wildcard with database, like --database=*, --database=greptime-* or --all. Note that we only have one catalog in self-hosted version so in most case it's like --all.

I think it's OK to have catalog/schema as an internal tool. But if we expose it as a user-facing tool we will need to explain those concepts.

[waynexia]

@sunng87 @shuiyisong PTAL

[sunng87]

LGTM.

But on top of this we may need authentication or tls setup to secure this tool.

[killme2008]

@shuiyisong PTAL

[killme2008]

@shuiyisong PTAL

[shuiyisong]

Export create table SQL works on v0.3 clusters