GH-5059 remove calls to E(...) when the return value is already being checked

[hmottestad]

GitHub issue resolved: #5059

Briefly describe the changes proposed in this PR:

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PR Author Checklist (see the contributor guidelines for more details):

• [ ] my pull request is self-contained
• [ ] I've added tests for the changes I made
• [ ] I've applied code formatting (you can use mvn process-resources to format from the command line)
• [ ] I've squashed my commits where necessary
• [ ] every commit message starts with the issue number (GH-xxxx) followed by a meaningful description of the change

[hmottestad]

@kenwenzel I've removed all the calls to E(...) where the return value was already being checked. Take a look if you can and feel free to merge if you are happy with everything. You can also create a release if you want, if not then I might have time the week of the 8th of July.

[kenwenzel]

Thank you. However, it helped us to find the empty key issue in the ValueStore. I will try to change that part to prevent looking up empty keys.