fix(server): save campaign - scenario link at scenario execution end

[rbenyoussef]

Issue Number

fixes #

Describe the changes you've made

Describe if there is any unusual behaviour of your code

Additional context

Test plan

Checklist

• Refer to issue(s) the PR solves
• New java code is covered by tests
• Add screenshots or gifs of the new behavior, if applicable.
• All new and existing tests pass
• No git conflict

[boddissattva]

When i have a campaign with parallel execution checked, i have error like :

11:34:59.269 [campaign-executor14] WARN o.h.e.jdbc.spi.SqlExceptionHelper - SQL Error: 5, SQLState: null
11:34:59.269 [campaign-executor14] ERROR o.h.e.jdbc.spi.SqlExceptionHelper - [SQLITE_BUSY] The database file is locked (database is locked)

And the campaign report does not reference all the scenario executions.

Bug case :
Create a scenario which sleep for a while with two extra copies.
Create campaign with these threes with parallel execution checked.
Execute the campaign.

[boddissattva]

Campaign parallel execution to fix.