Modify Writer_DocOpen Connection Method, minor formatting changes

[donnyh13]

Pull request

Proposed changes

Describe the big picture of your changes here to communicate to the maintainers why we should accept this pull request.
Please ensure you have read and noticed the checklist below.

Checklist

Put an x in the boxes that apply. If you're unsure about any of them, don't hesitate to ask. We are here to help!
This is simply a reminder of what we are going to look for before merging your code.

• [x] I have read and noticed the CODE OF CONDUCT document
• [x] I have read and noticed the CONTRIBUTING document
• [x] I have added necessary documentation or screenshots (if appropriate)
• [x] I have tested my changes or additions for proper functionality.
• [x] I have followed, as best as possible, the same function layout and coding style of other existing functions/code.

Types of changes

Please check x the type of change your PR introduces:

• [x] Bugfix (change which fixes an issue)
• [ ] Feature (change which adds functionality)
• [ ] Code style update (formatting, renaming)
• [ ] Refactoring (functional, structural)
• [x] Documentation content changes
• [ ] Other (please describe)
  ** |-->:

What is the current behavior?

Please describe the current behavior that you are modifying, or link to a relevant issue.
** |-->:

• Previous method of connecting to an already opened document relied on a certain COM Error being present, which no longer appears. Also the document would cause certain errors when being connected to using the previous method.

What is the new behavior?

Please describe the behavior or changes that are being added by this PR.
** |-->:

• I now made the function check for a an already open document with the same save path first, before trying to open the document.

Influences and relationship to other functionality

Describe how the changes will affect other functions, potential script breaking changes, etc.
** |-->:

Additional context

Add any other context about the problem here.
** |-->:

System under test

Please complete the following information.

• OS: [e.g. Windows 10]
• OS Arch.: [e.g. X64]
• LibreOffice Component: [e.g. Main, Writer, Calc]
• LibreOffice version: [e.g. 7.3.4.2]

[donnyh13]

• Added Fill Style Retrieval functions
• Rename Internal Constant $__LOWCONST_FILLSTYLE to $LOW_AREA_FILLSTYLE This allows the user to determine what Background Fill Style is currently being used.