Add invert lightness theme

[CrazyBlobie]

Add invert lightness theme like Okular, which instead of investing the colors directly, only invests the brightness.

Also look into other theme settings like in Okular By KDE.

Instead of just single color theme, allow advanced users to put a snippet of code logic in which tells the theme engine how to change colors.

[CrazyBlobie]

Also, a big option to hide annotations quickly, and also remove bulk hyperlinks (when you download pesky shady books and the author plug their telegram or external link into every page)... Remove using a similar script, here's a example one to tell u what i mean:

from pypdf import PdfReader, PdfWriter
import sys

if len(sys.argv) != 3:
    print(f"Usage: {sys.argv[0]} input.pdf output.pdf")
    sys.exit(1)

reader = PdfReader(sys.argv[1])
writer = PdfWriter()

for page in reader.pages:
    # Remove all annotations (including hyperlinks)
    page.pop("/Annots", None)
    writer.add_page(page)

with open(sys.argv[2], "wb") as f:
    writer.write(f)

print("It's done.")