Improved Apprise general text conversion support

[caronc]

Description:

Related issue (if applicable): #565

Greatly improved Telegram test cases to accommodate bug issue raised. Text Conversion enhanced to support titles.

Checklist

• The code change is tested and works locally.
• There is no commented out code in this PR.
• No lint errors (use flake8)
• 100% test coverage

Testing

Anyone can help test this source code as follows:

# Create a virtual environment to work in
# This way you can just destroy it after when it's all over.
# The below will create a directory called apprise
python3 -m venv apprise

# Change into our new directory
cd apprise

# Activate our virtual environment
source bin/activate

# Install the branch
pip install git+https://github.com/caronc/apprise.git@565-telegram-html-titles

# Run Telegram Tests
apprise telegram://credentials

[codecov-commenter]

Codecov Report

Merging #566 (b6c968f) into master (b28cd4c) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##            master      #566    +/-   ##
==========================================
  Coverage   100.00%   100.00%            
==========================================
  Files          107       107            
  Lines        13905     14416   +511     
  Branches      2600      2773   +173     
==========================================
+ Hits         13905     14416   +511     

Impacted Files	Coverage Δ
apprise/Apprise.py	100.00% <100.00%> (ø)
apprise/AppriseAsset.py	100.00% <100.00%> (ø)
apprise/conversion.py	100.00% <100.00%> (ø)
apprise/plugins/NotifyTelegram.py	100.00% <100.00%> (ø)
apprise/utils.py	100.00% <0.00%> (ø)
apprise/common.py	100.00% <0.00%> (ø)
apprise/AppriseConfig.py	100.00% <0.00%> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update b28cd4c...b6c968f. Read the comment docs.