linkifiers: Add `title` attribute to `Delete` button.
linkifiers: Add `title` attribute to `Delete` button.

This commit adds `title` attribute and removes
`aria-hidden` attribute in `Delete` button in
linkifiers table.

`aria-hidden` attribute is used only for icons on buttons
that have a plain-text label.

kou/zulip,kou/zulip,punchagan/zulip,rht/zulip,punchagan/zulip,rht/zulip,hackerkid/zulip,punchagan/zulip,kou/zulip,zulip/zulip,hackerkid/zulip,punchagan/zulip,kou/zulip,rht/zulip,eeshangarg/zulip,rht/zulip,andersk/zulip,eeshangarg/zulip,eeshangarg/zulip,zulip/zulip,zulip/zulip,rht/zulip,andersk/zulip,eeshangarg/zulip,andersk/zulip,eeshangarg/zulip,andersk/zulip,punchagan/zulip,punchagan/zulip,zulip/zulip,hackerkid/zulip,andersk/zulip,hackerkid/zulip,hackerkid/zulip,hackerkid/zulip,zulip/zulip,andersk/zulip,rht/zulip,rht/zulip,kou/zulip,eeshangarg/zulip,kou/zulip,zulip/zulip,kou/zulip,andersk/zulip,punchagan/zulip,hackerkid/zulip,eeshangarg/zulip,zulip/zulip