Bad rotation_mode/center_baseline combination even if rotation=0 #13028

Bug report

Bug summary

When rotation_mode='anchor' and "verticalaligment="center_baseline", the vertical alignment is wrong even if ``rotation=0```.

Code for reproduction

import matplotlib.pyplot as plt

plt.plot([0, 1], lw=0)
plt.axvline(.5, linewidth=.5, color='.5')
plt.axhline(.5, linewidth=.5, color='.5')
plt.text(.5, .5, 'pP', color='k', size=100, va='center_baseline')
plt.text(.5, .5, 'pP', color='tab:red', size=100, va='center_baseline', rotation_mode='anchor')

Actual outcome

Expected outcome

Same alignment in this case.

Matplotlib version

• Operating system: linux
• Matplotlib version: 3.0.2
• Matplotlib backend (print(matplotlib.get_backend())): agg, tkagg
• Python version: 3.6
• Jupyter version (if applicable):
• Other libraries:

Installed via conda.