test: add '_stress' suffix to election_qsync test

The test is long, about 10 seconds. But its name is too general.
And it would be better used for a simpler more basic test. This is
going to happen in the next commits.

election_qsync.test.lua will check if the election and qsync work
fine together without any stress cases.

Needed for #5339

test/replication/suite.ini

@@ -113,7 +113,7 @@ fragile = {
             "issues": [ "gh-5381" ],
             "checksums": [ "a73b46d27fc48d2d7016597eeadbed2c" ]
         },
-        "election_qsync.test.lua": {
+        "election_qsync_stress.test.lua": {
             "issues": [ "gh-5395" ],
             "checksums": [ "55ccd87be70d4cb818c8d4dd43a8a2f9", "cc93d7c69c6368217634718bdf3de16c", "3fb2e6cef4c8fa1d0edd8654fd2d8ef6", "2f03ab89040bf2435a9fab8a1cddc990", "2870483307db27542796a3b2cf76a9f1", "2c21702af2ed09ae0f0d7cf651eb5646", "ac2c562932ea624c6ffbf7f7671c9803", "1aec2786b758bf7dc408a83c2e83c37d", "37e671aea27e3396098f9d13c7fa7316", "ca38ff2cdfa65b3defb26607b24454c6", "eb43a3f7feaa629a474a144665b6d3d6", "6e1d222f2cf5d8c437e572784c748489a", "bcab5da1daa9feb85b75ade6285934ea", "57191f7c3b108d34a06b4172ef88d676", "dc89f0d78ee7a6321b95af96159bd6c4", "2cb9873226dbf765d539b0143174635b", "7ccb7455c4c58a8cc64fff02ce8e9b37", "1e31ad3a916708a77da75485b6febdcd", "553c91d230489534d500fc441b5708da", "142a059788b39c5f252d83357b1e59a3", "6d0e40a1556254cdacc7afa35f298633", "eb1b45595ffabb01c2f7599b74531111", "259bde2222cc8368db35a348c74146b4", "ce44ea01d3621ef9796f5769a061edd6", "5be4e1cc9120e60dd433547745979024", "16b9325575cc12f7f9630c581caa425a", "3a6def04cf9624969883ee967c4cdf68", "3196fdcad898d99295b675668b00a7cf", "32797413e2d2a61eab5e39e8eccf6d82", "7ec7ab20c83ff8d06d6c6911af7ed54b", "216012f2e376d3712825bbb0412a9920", "f68cb670318f744645ab82935ca91f8b", "a1e897328d7a4c84e8557a9c64858771", "114360fccdaa8408609d5536e2fc4fcb", "51421bd96547351b0695784310c7fc41", "ebb760957c9d30a5e2453df3891d991b", "4a82db713bca762cdfc04e0ed539e60b", "0375dee5560bd34fd83140a2a24437e5", "a0302ead43647f7489c83bb12b54853d", "4b1268d16c9826a61036ef36cb04cc80", "2363b71ed7b4a3cff9dbf5ae1d29d36e", "463c9bccef60915ea55d1875125eb6bb", "d459b6ab666f3b21214ef6efe3d0989f", "b0a0893162e8fe43cad023d3857ff3ba", "013f7a4a36c36603e8156be120f07e2c", "f749c06bcf4a2c8e7c55251df700acd1", "f0d248af7c764fda6d98f5f1b3d6310a", "fc835fcd850db2e1030af34dd97b68b5", "321b0c2f7343da3c14a4f7e00932ed1c", "796fb7996d6b2e5859b862887b3471f9", "ce8d19167542bd2b2eb6a9b66ff31f08", "fb39d69b94eea968781e71ddd9d30c63", "e242f5f0cff02af325351a9a01043828", "8a36ef30432cda293c689ff8524f6644", "ea9b9d01e95834cfd5cd332cb40461fe", "951106fbf2872bb935912110f11b7fa9" ]
         },