Bugfix/postgres-like

changed way to perform searches:
* only search on numeric fields if search is numeric
* else just search on text fields

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- [x] test coverage
- [x] gather feedback for my changes


| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | yes
| Tests pass?   | yes
| Fixed tickets | none
| Doc           | <url to doc>