fix: include vector_utils in ImagingClusterReco

[wdconinc]

Briefly, what does this PR introduce?

ImagingClusterReco uses multiplication of Vector3f with float, which is defined in vector_utils. IWYU has trouble with operators.

What kind of change does this PR introduce?

• [x] Bug fix (issue: fails to compile when header is used separately, not in BEMC.cc)
• [ ] New feature (issue #__)
• [ ] Documentation update
• [ ] Other: __

Please check if this PR fulfills the following:

• [ ] Tests for the changes have been added
• [ ] Documentation has been added / updated
• [ ] Changes have been communicated to collaborators

Does this PR introduce breaking changes? What changes might users need to make to their code?

No.

Does this PR change default behavior?

No.

[github-actions[bot]]

Capybara summary for PR 1482

• rec_dis_10x100_minQ2=0_craterlake
• rec_dis_10x100_minQ2=1000_craterlake
• rec_dis_18x275_minQ2=0_craterlake
• rec_dis_18x275_minQ2=1000_craterlake
• rec_dis_5x41_minQ2=0_craterlake
• rec_e_1GeV_20GeV_craterlake
• rec_pi_1GeV_20GeV_craterlake ^{_{Last updated 2024-06-03T13:52-04:00 2e4ffac3268f5032505759d41dfaff311a461dfa}}