edit_history: Respect time format setting (12h/24h).
edit_history: Respect time format setting (12h/24h).

Previously, the edit history modal did not respect the time format
setting (whether to show times in 12-hour or 24-hour format) when
displaying message edit times (#15171).

This commit fixes that by passing the edit times to
timerender.stringify_time(), which takes that setting into account,
instead of just doing a static string formatting operation.

This bug has existed since February 2017, when the edit history UI
was first added in 1a697b6e02b03cf714c9ab0fd51dfabe8752ba35.

Fixes #15171.

punchagan/zulip,showell/zulip,brainwane/zulip,punchagan/zulip,kou/zulip,timabbott/zulip,showell/zulip,eeshangarg/zulip,showell/zulip,rht/zulip,zulip/zulip,punchagan/zulip,timabbott/zulip,synicalsyntax/zulip,zulip/zulip,showell/zulip,eeshangarg/zulip,kou/zulip,hackerkid/zulip,synicalsyntax/zulip,kou/zulip,rht/zulip,eeshangarg/zulip,hackerkid/zulip,eeshangarg/zulip,kou/zulip,shubhamdhama/zulip,showell/zulip,andersk/zulip,hackerkid/zulip,timabbott/zulip,hackerkid/zulip,zulip/zulip,kou/zulip,punchagan/zulip,kou/zulip,eeshangarg/zulip,hackerkid/zulip,shubhamdhama/zulip,shubhamdhama/zulip,rht/zulip,kou/zulip,shubhamdhama/zulip,andersk/zulip,punchagan/zulip,timabbott/zulip,andersk/zulip,brainwane/zulip,brainwane/zulip,hackerkid/zulip,synicalsyntax/zulip,zulip/zulip,andersk/zulip,synicalsyntax/zulip,timabbott/zulip,timabbott/zulip,brainwane/zulip,shubhamdhama/zulip,shubhamdhama/zulip,rht/zulip,zulip/zulip,andersk/zulip,punchagan/zulip,andersk/zulip,timabbott/zulip,eeshangarg/zulip,andersk/zulip,brainwane/zulip,punchagan/zulip,synicalsyntax/zulip,rht/zulip,eeshangarg/zulip,brainwane/zulip,zulip/zulip,synicalsyntax/zulip,zulip/zulip,rht/zulip,showell/zulip,rht/zulip,shubhamdhama/zulip,brainwane/zulip,hackerkid/zulip,showell/zulip,synicalsyntax/zulip