…et#259)

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### Description of PR
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Summary:
Fixes # (issue)
This test plan is to test if control/data plane can handle the initialization/flapping of numerous BGP session holding a lot routes, and estimate the impact on it.

Related PRs:
| PR title | State | Context |
| ------ | ------ | -------|
| [ [bgp-scale-test] Implement bgp scale test cases for sessions flapping, unisolation, nexthop group member change scenarios ](sonic-net#16069) | ![state](https://img.shields.io/github/pulls/detail/state/sonic-net/sonic-mgmt/16069) | ![context](https://img.shields.io/github/status/contexts/pulls/sonic-net/sonic-mgmt/16069) |
| [ [testbed] announce routes with routes generation switch, aggregate routes and variable ipv6 address pattern ](sonic-net#15748) | ![state](https://img.shields.io/github/pulls/detail/state/sonic-net/sonic-mgmt/15748) | ![context](https://img.shields.io/github/status/contexts/pulls/sonic-net/sonic-mgmt/15748) |
| [ [isolated-topo] disable ipv4 routes generation, add mocked aggregated addresses ](sonic-net#15748) | ![state](https://img.shields.io/github/pulls/detail/state/sonic-net/sonic-mgmt/16213) | ![context](https://img.shields.io/github/status/contexts/pulls/sonic-net/sonic-mgmt/16213) |

### Type of change

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- [x] Bug fix
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- [ ] Bug fix
- [ ] Testbed and Framework(new/improvement)
- [ ] Test case(new/improvement)

### Back port request
- [ ] 202012
- [ ] 202205
- [ ] 202305
- [ ] 202311
- [ ] 202405

### Approach
#### What is the motivation for this PR?
With numerous BGP sessions holding a lot routes, any flapping on BGP sessions or routes cloud have more overhead on device, to verify the functionality and estimate convergence time, we publish this test plan.
#### How did you do it?
Describe three test scenarios and introduce how we measure time in test.
#### How did you verify/test it?

#### Any platform specific information?

#### Supported testbed topology if it's a new test case?

### Documentation
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(If it's a new feature, new test case)
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…ic-net#2530)

* [sub module] sub module sonic-swss-common tracking 201811 branch

And include change:

Submodule src/sonic-swss-common e8caaea..a40837a:
  > [pyext] enable types in stdint.h (sonic-net#259)

Signed-off-by: Ying Xie <ying.xie@microsoft.com>

* also include:

Submodule src/sonic-swss-common a40837a..594f4e8:
  > Optimized ProducerStateTable set/del notification processing to avoid… (sonic-net#257)

Signed-off-by: Ying Xie <ying.xie@microsoft.com>