[df] Add ChangeBeginAndEndEntries

[kristupaspranc]

[github-actions[bot]]

Test Results

    12 files      12 suites   2d 8h 0m 14s :stopwatch:  2 609 tests  2 602 :white_check_mark: 0 :zzz:  7 :x: 29 344 runs  29 275 :white_check_mark: 0 :zzz: 69 :x:

For more details on these failures, see this check.

Results for commit 380cc5b6.

[kristupaspranc]

As a stand alone function, it works as expected, but applying it before other actions, namely Cache and Foreach, distorts them.

[kristupaspranc]

Made the requested changes, added a test. This function has nothing to do with Foreach as previously reported. It only works with dataframes that are made out of TTree or TChain as intended, thus, it does not with a dataframe that is Cached.