Base_Engine: Even log interference with analytics at startup

#### Description:

https://github.com/BHoM/BHoM_Engine/pull/2750 had an unforeseen impact on the behaviour on start-up for some edge cases. As the Eventlog is no longer Thread Static, this means that any events raised by the analytics will be captured in the same CurrentEvents log as the production code running. This can have an impact on opening scripts at the same time as the analytics is running.

#### Steps to reproduce:

An example of when this can become an issue is:
1. User switches to a branch that has added objects and or methods and runs a testing script with those objects/methods
2. Close the script, and switch to another branch without those objects/methods and rebuild
3. Open a script that uses BHoM, but do not have the named objects/methods in it.
4. Errors from failing to deserialise the objects/methods from the branch can appear on components that have nothing to do with those objects/methods:
5. Re-running the script makes all the errors disappear:

#### Expected behaviour:

For the Event log to be able to handle multiple threads in the production code, to allow notes/warnings and errors to be captured during parallel running of methods, but for other tasks running on the same process to not interfere with the log.

#### Test file(s):