[lldb] [disassembler] chore: add GetVariableAnnotations to SBInstruction api (#177676)
## Description
Contribution to this topic [Rich Disassembler for
LLDB](https://discourse.llvm.org/t/rich-disassembler-for-lldb/76952),
this part.
```
The rich disassembler output should be exposed as structured data and made available through LLDB’s scripting API so more tooling could be built on top of this
```
----
This pr replaces #174847
As was suggested in [this
comment](https://github.com/llvm/llvm-project/pull/174847#issuecomment-3757015552),
implement access to variable annotations from `SBInstruction` class
itself.
Notes:
- :white_check_mark: did run black formatter on the python file;
## Testing
Run test with
```sh
./build/bin/lldb-dotest -v -p TestVariableAnnotationsDisassembler.py lldb/test/API/functionalities/disassembler-variables
```
all tests (9 existing + 1 newly added) are passing
<details>
<summary>screenshot 2026-01-23</summary>
build from the latest commit 08f00730b5768a8e3f7039d810084fabaaa24470
<img width="1506" height="562" alt="image"
src="https://github.com/user-attachments/assets/69516353-3432-47df-ae45-c40b51ec14c4"
/>
</details>
<details>
<summary>screenshot 2026-01-29</summary>
build from the latest commit f48a1a2c10f96a457ca6844be2ccc9406d3d57a0
<img width="1232" height="740" alt="image"
src="https://github.com/user-attachments/assets/9d104ce6-36c3-430b-98fe-f028f83a6b6d"
/>
</details>
---------
Signed-off-by: Nikita B <n2h9z4@gmail.com>