### Is there an existing issue for the same bug?
- [X] I have checked the existing issues.
### Version or Commit ID
92eab12f5c656d94a26fc31c904a1dc73c885d74
### Other environment information
_...
### What problem does this PR solve?
New HTTP examples:
- Show table segments
- Show table blocks
- Drop table columns
- Show index segments
- Show index chunk
- Show table block
- Show t...
### What problem does this PR solve?
New HTTP examples:
- Show table segments
- Show table blocks
- Drop table columns
- Show index segments
- Show index chunk
Issue link: #1937
### T...
### What problem does this PR solve?
Add examples for altering showing metadatas:
- Show segments.
- Show blocks.
- Drop a column.
Issue link: #1937
### Type of change
- [x] Other (...
### What problem does this PR solve?
_Add examples for showing metadatas._
Issue link: #1937
### Type of change
- [x] Other (please describe): new examples.