Clean summary cache on node up and summary

[Neylix]

Description

Fixes the issue where sometime the summary cache was not properly cleaned and so could create a summary with 2 summary inside.
Now 2 summary backup are kept, the current one and the previous one.
The previous summary slots in ets table are cleared right after being uses by subset.
On event node_up, backup file and ets table is cleaned.

Fixes #1138

Type of change

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Unit test

Runned 2 nodes, send to one a node_down event before a summary and send a node_up after the summary, ets table is cleaned as expected.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules