Add support for brotli gz compression in htaccess.txt

From Wikipedia:

Brotli is a lossless data compression algorithm developed by Google. It uses a combination of the general-purpose LZ77 lossless compression algorithm, Huffman coding and 2nd-order context modelling. Brotli is primarily used by web servers and content delivery networks to compress HTTP content, making internet websites load faster. A successor to gzip, it is supported by all major web browsers and has become increasingly popular, as it provides better compression than gzip.

Summary of Changes

Webservers that use brotli and have Joomla's htaccess enabled will fail the website in HTTPS unless you comment/delete the code block related to GZIP.
After the change, the problem no longer occurs.

Testing Instructions

1. Check if your hosting uses brotli.
2. Apply the patch and copy the text from htaccess.txt to .htaccess
3. Indicate in the test whether you tested with a hosting that uses brotli or not. I think it is useful to have tests for both cases.

Actual result BEFORE applying this Pull Request

If your hosting does not use brotli

Joomla works properly

If your hosting use brotli

Joomla in HTTP works correctly.
Joomla in HTTPS does not load the CSS and JS resources, and investigating the error in the console is: ERR_CONTENT_DECODING_FAILED

Expected result AFTER applying this Pull Request

If your hosting does not use brotli

Joomla still works properly

If your hosting use brotli

Joomla works properly

NOTE

ServerPlan uses brotli.

Thanks

Thanks to ServerPlan for supporting the tests and finding the solution

Link to documentations

Please select:

• Documentation link for docs.joomla.org:

• No documentation changes for docs.joomla.org needed

• Pull Request link for manual.joomla.org:

• No documentation changes for manual.joomla.org needed