[Bug]: Relative paths for Literalincludes in included files are resolved incorretly

Summary

Relative paths are resolved from the location where the file is included not from the location oft the file itself

Code snippet that reproduces the problem

I have the following directory structures:

They are all included in Index.rst

Now if one of the properties or examples has a literalinclude using relativ paths I would expect the following to work:

..  literalinclude:: ../_CodeSnippets/_creationOptions.php
    :language: php
    :caption: EXT:my_extension/Configuration/TCA/Overrides/tt_content.php

But have to do

..  literalinclude:: _CodeSnippets/_creationOptions.php
    :language: php
    :caption: EXT:my_extension/Configuration/TCA/Overrides/tt_content.php

Or an absolute path like

..  literalinclude:: /Types/_CodeSnippets/_creationOptions.php
    :language: php
    :caption: EXT:my_extension/Configuration/TCA/Overrides/tt_content.php

Expected output

I would expect

..  literalinclude:: ../_CodeSnippets/_creationOptions.php
    :language: php
    :caption: EXT:my_extension/Configuration/TCA/Overrides/tt_content.php

To work

Reproduce the issue with the shown included-file structure and the relative literalinclude examples. Compare resolution from the including file with resolution from the file containing the directive; done means the ../_CodeSnippets/_creationOptions.php path works as shown while preserving the expected code output.