Add new method appendIccProfile to fix quadratic performance issue (backport #3335)

[mergify]

Fixes: #3333

The code in jpgimage.cpp was quadratic because it was appending bytes to the end of the iccProfile by copying the entire array every time. This PR adds an appendIccProfile method so that the bytes can be appended efficiently.

---

This is an automatic backport of pull request #3335 done by Mergify.

[mergify]

Cherry-pick of 472d55e has failed:

On branch mergify/bp/0.28.x/pr-3335
Your branch is up to date with 'origin/0.28.x'.

You are currently cherry-picking commit 472d55ed.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	modified:   include/exiv2/image.hpp
	modified:   src/image.cpp

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   src/jpgimage.cpp

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[codecov]

Codecov Report

❌ Patch coverage is 76.47059% with 4 lines in your changes missing coverage. Please review.
✅ Project coverage is 64.70%. Comparing base (e0e09f9) to head (b7f153f).
⚠️ Report is 51 commits behind head on 0.28.x.

Files with missing lines	Patch %	Lines
src/image.cpp	75.00%	2 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           0.28.x    #3345      +/-   ##
==========================================
+ Coverage   64.68%   64.70%   +0.02%     
==========================================
  Files         104      104              
  Lines       22241    22238       -3     
  Branches    10887    10863      -24     
==========================================
+ Hits        14386    14390       +4     
- Misses       5604     5605       +1     
+ Partials     2251     2243       -8     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.