rest-api: When finding table items by cell value, ignore BiDi control chars

[mvidner]

• continuation of https://trello.com/c/GZXM36ty
• a failed openQA test prompting this: https://openqa.opensuse.org/tests/1740438#step/raid_gpt/4
• https://bugzilla.suse.com/show_bug.cgi?id=1128091

In yast/yast-storage-ng#873 I have fixed displaying filesystem paths in partitioner table widgets in right to left languages, by adding invisible BiDirectional control characters to the paths (which Qt then interprets and lays out the text correctly).

Part of that was adjusting the unit tests that were comparing table cell values to cope with the added characters and strip them off before comparing with expected values. What I haven't expected, similar comparisons are done by production code, namely here by libyui-rest-api when choosing widgets and their items by their text values.

The fix is to strip the BiDi control characters before the comparison.

openQA includes an automated test. Here is a manual test:

YUI_HTTP_REMOTE=1 YUI_REUSE_PORT=1 YUI_HTTP_PORT=9999 yast2 disk &
# now press Enter to confirm that you're not afraid of touching disks
# now select one of the partitions to move the cursor away from the whole disk, `/dev/vda`
# edit the disk name below if you have `sda` instead
curl -v -X POST 'http://localhost:9999/v1/widgets?id=%22Y2Partitioner::Widgets::ConfigurableBlkDevicesTable%22&action=select&value=/dev/vda'
# response to the above command will be 200 OK and the cursor will move

• recently libyui-rest-api was improved to disregard the & keyboard shortcut marker in widget labels. This PR should take that into account and use similar code.
• version + changelog

[shundhammer]

LGTM.

Now we'll have to rely on our QA people to check this in the real openQA machinery.

[mvidner]

This is the actual fix.

[shundhammer]

It took me a while to understand how that remove_if() works (in true STL manner, designed in a mathematically correct way, but not at all practically oriented, let alone easy to understand; that's why I prefer Qt's string and container classes), but now that I got that,

LGTM.