There is no way to prevent Blogger from doing this: the Post-editor does not support all aspects of HTML, and so some unsupported elements that you add will be removed (e.g., <p> tags), while others (e.g., tables) will be kept even though there is no way to create them in Compose mode.
I do not have a list of which HTML elements are and are not ...
GitHub uses Markdown (specifically a custom 'flavour' thereof), and in Markdown you can escape backticks in code by using double backticks: https://github.com/mattcone/markdown-guide/blob/master/_basic-syntax/code.md#escaping-backticks
If the word or phrase you want to denote as code includes one or more backticks, you can escape it by enclosing the word ...
How to know if Google Sheets IMPORTDATA, IMPORTFEED, IMPORTHTML or IMPORTXML functions are able to get data from a ...
This is the closest I have been able to get:
Upload your HTML file to google drive
Open the file by double-clicking and select "open with google docs"
This way docs will try as much as it can to render the data.
what I got: