Rollup merge of #152226 - fmease:modernize-indeterminate-object-lifetime-diag, r=chenyukang

Modernize diagnostic for indeterminate trait object lifetime bounds

* remove suggestion from the diagnostic message (bad style, too long) and turn it into a structured suggestion
* replace *object type* with *trait object type* since the former is an outdated term

Author: JonathanBrouwer