[TTreeReader][ROOT-10046] Treat ideantically TTree and TChain

[dpiparo]

when it comes to branch names which contain a dot.

[phsft-bot]

Starting build on ROOT-performance-centos7-multicore/default, ROOT-fedora27/noimt, ROOT-fedora29/python3, ROOT-ubuntu16/rtcxxmod, ROOT-ubuntu18.04-i386/cxx14, mac1014/cxx17, windows10/default
How to customize builds

[phsft-bot]

Build failed on mac1014/cxx17.
See console output.

Warnings:

• CMake Warning at /build/jenkins/workspace/root-pullrequests-build/rootspi/jenkins/root-build.cmake:801 (message):

Failing tests:

• projectroot.roottest.root.tree.reader.roottest_root_tree_reader_test_oddName

[phsft-bot]

Build failed on ROOT-performance-centos7-multicore/default.
See console output.

Warnings:

• CMake Warning at /data/sftnight/workspace/root-pullrequests-build/rootspi/jenkins/root-build.cmake:801 (message):

Failing tests:

• projectroot.roottest.root.tree.reader.roottest_root_tree_reader_test_oddName

[phsft-bot]

Build failed on ROOT-fedora27/noimt.
See console output.

Warnings:

• CMake Warning at /mnt/build/workspace/root-pullrequests-build/rootspi/jenkins/root-build.cmake:801 (message):

Failing tests:

• projectroot.roottest.root.tree.reader.roottest_root_tree_reader_test_oddName

[phsft-bot]

Build failed on ROOT-ubuntu18.04-i386/cxx14.
See console output.

Warnings:

• CMake Warning at /mnt/build/workspace/root-pullrequests-build/rootspi/jenkins/root-build.cmake:801 (message):

Failing tests:

• projectroot.tree.tree.test.gtest_tree_tree_test_testBulkApiMultiple
• projectroot.tree.tree.test.gtest_tree_tree_test_testBulkApiSillyStruct
• projectroot.tree.tree.test.gtest_tree_tree_test_testBulkApiVarLength
• projectroot.roottest.root.tree.fastcloning.roottest_root_tree_fastcloning_execCheckClusterRange