move message into own namespace

[DavidBadura]

Deptrac showed me that a lot of things depend on the event bus through the message, even though these components have nothing to do with it. They just share the message. That's why I've now removed message as its own component, which makes more sense in my opinion.

[github-actions]

Hello 👋

here is the most recent benchmark result:

SnapshotsBench
==============

+----------------------------------------+--------------------+--------------------+-----------------+------------+
|                                        | time (kde mode)                         | memory                       |
+----------------------------------------+--------------------+--------------------+-----------------+------------+
| subject                                | Tag: <current>     | Tag: base          | Tag: <current>  | Tag: base  |
+----------------------------------------+--------------------+--------------------+-----------------+------------+
| benchLoad10000EventsMissingSnapshot () | 153.156ms (±0.00%) | 152.682ms (±0.00%) | 38.664mb        | 38.666mb   |
| benchLoad10000Events ()                | 520.900μs (±0.00%) | 522.500μs (±0.00%) | 38.664mb        | 38.665mb   |
+----------------------------------------+--------------------+--------------------+-----------------+------------+

SimpleSetupBench
================

+----------------------------------------+--------------------+--------------------+-----------------+------------+
|                                        | time (kde mode)                         | memory                       |
+----------------------------------------+--------------------+--------------------+-----------------+------------+
| subject                                | Tag: <current>     | Tag: base          | Tag: <current>  | Tag: base  |
+----------------------------------------+--------------------+--------------------+-----------------+------------+
| benchLoad10000Events ()                | 156.508ms (±0.00%) | 154.982ms (±0.00%) | 38.667mb        | 38.669mb   |
| benchSave1Event ()                     | 868.700μs (±0.00%) | 870.300μs (±0.00%) | 38.667mb        | 38.668mb   |
| benchSave10000Events ()                | 457.459ms (±0.00%) | 478.935ms (±0.00%) | 38.933mb        | 38.935mb   |
| benchSave10000Aggregates ()            | 9.144s (±0.00%)    | 9.371s (±0.00%)    | 38.667mb        | 38.669mb   |
| benchSave10000AggregatesTransaction () | 7.425s (±0.00%)    | 7.435s (±0.00%)    | 38.667mb        | 38.669mb   |
+----------------------------------------+--------------------+--------------------+-----------------+------------+

SubscriptionEngineBench
=======================

+---------------------------+-----------------+-----------------+-----------------+------------+
|                           | time (kde mode)                   | memory                       |
+---------------------------+-----------------+-----------------+-----------------+------------+
| subject                   | Tag: <current>  | Tag: base       | Tag: <current>  | Tag: base  |
+---------------------------+-----------------+-----------------+-----------------+------------+
| benchHandle10000Events () | 3.214s (±0.00%) | 3.217s (±0.00%) | 39.066mb        | 39.068mb   |
+---------------------------+-----------------+-----------------+-----------------+------------+

SplitStreamBench
================

+-------------------------+--------------------+--------------------+-----------------+------------+
|                         | time (kde mode)                         | memory                       |
+-------------------------+--------------------+--------------------+-----------------+------------+
| subject                 | Tag: <current>     | Tag: base          | Tag: <current>  | Tag: base  |
+-------------------------+--------------------+--------------------+-----------------+------------+
| benchLoad10000Events () | 5.397ms (±0.00%)   | 5.443ms (±0.00%)   | 42.532mb        | 42.533mb   |
| benchSave10000Events () | 605.351ms (±0.00%) | 615.229ms (±0.00%) | 42.809mb        | 42.811mb   |
+-------------------------+--------------------+--------------------+-----------------+------------+

This comment gets update everytime a new commit comes in!