Refactor Builder API before documentation

[FabienLelaquais]

Addresses doc#533.

[github-actions[bot]]

Coverage report for gui

St.:grey_question:	Category	Percentage	Covered / Total
🟢	Statements	80.48%	2226/2766
🟡	Branches	61.84%	1345/2175
🟡	Functions	74.95%	389/519
🟢	Lines	80.88%	2064/2552

Test suite run success

317 tests passing in 35 suites.

Report generated by 🧪jest coverage report action from f593d7309bd582666f6355b06374b422115fbd5d

[github-actions[bot]]

☂️ Python Coverage

current status: ✅

Overall Coverage

Lines	Covered	Coverage	Threshold	Status
5203	4485	86%	85%	🟢

New Files

No new covered files...

Modified Files

File	Coverage	Status
src/taipy/gui/init.py	100%	🟢
src/taipy/gui/_renderers/init.py	90%	🟢
src/taipy/gui/builder/init.py	100%	🟢
src/taipy/gui/builder/page.py	70%	🟢
src/taipy/gui/gui.py	90%	🟢
src/taipy/gui/page.py	91%	🟢
TOTAL	90%	🟢

updated for commit: f593d73 by action🐍