Add support for depth and case sensitivity in directory exclusions, by directory

[ghecko]

Enhanced --exclude-dir to accept the format DIRNAME[:DEPTH[:CASE]], allowing users to define:

• DEPTH: Specify recursion depth. -1 for all depths, default is 0 (current directory only).
• CASE: Specify case sensitivity. i for case-insensitive, or s for case-sensitive (default).

Example

Exclude directories named snapshot at current directory level, case-sensitive (default):

find -iname "*.ps1" --exclude-dir snapshot .

Exclude temp directories until depth 2, case-insensitive:

find -iname "*.ps1" --exclude-dir temp:2:i .

Exclude multiple directory:

find -iname "*.ps1" --exclude-dir temp:2:i --exclude .git:-1 .

[p0dalirius]

Thank you for the PR!