Some less serious search warnings should be reclassified as info such as string truncations and the icon should reflect max severity

[stroomdev66]

[at055612]

@stroomworks1876 Re-opened this is it is not working, see #5224. I made some changes (see https://github.com/gchq/stroom/compare/gh-5224-no-match-found?expand=1) before I realised this was an un-finished change.

Over to you.