Title: setImageValue default limit does not behave as "unlimited"

[adq-talbot]

Issue

setValueForPart treats MAXIMUM_REPLACEMENTS_DEFAULT as unlimited replacements. setImageValue does not. When setImageValue is called without an explicit $limit, replacement is inconsistent:

If all placeholder occurrences are byte-for-byte identical (e.g. repeated <w:t>${Image}</w:t>), all are replaced.
If placeholders differ in formatting/whitespace (e.g. <w:t xml:space="preserve"> ${Image}</w:t> vs <w:t>${Image}</w:t>), only the first occurrence is replaced.

Actual behavior

Only the first occurrence is replaced if placeholders are not exactly identical in the XML.

Workaround

Pass an explicit very large limit to simulate "no limit":

$templateProcessor->setImageValue('Image', $image, PHP_INT_MAX);

Note: this workaround has a minor side effect. addImageToRelations may be called for images that were already replaced. That adds duplicate relation entries to the generated .docx and introduces a small performance cost. This can be addressed in the same fix by avoiding duplicate relation additions or checking for existing relations before adding.

Proposed solution

Make setImageValue treat MAXIMUM_REPLACEMENTS_DEFAULT as unlimited, consistent with setValueForPart.

Prevent duplicate addImageToRelations calls when using unlimited replacements.

Expected behavior

All placeholders should be replaced consistently when the default limit is used, matching setValueForPart behavior where MAXIMUM_REPLACEMENTS_DEFAULT means no limit.

Steps to reproduce

XML:

<w:t xml:space="preserve"> ${Image}</w:t>
<w:t>${Image}</w:t>

Call:

$templateProcessor->setImageValue('Image', $image);

Next steps

I can open a pull request with the fix and tests if maintainers agree.

PHPWord version(s) where the bug happened

1.4

PHP version(s) where the bug happened

8.4