Enhance the SUM() aggregate (and related AVG() and TOTAL()) so that the running

sum is accurate to about 100 bits.

FossilOrigin-Name: a915f15a916af698e0cef46c8b3e7ed11bda19349179d2d414073cd39c4cce24

diff --cc manifest
index 8cd8dc169f9bb5af1b3ab19678e98061d474678f,61c172494c1dff19259687621daa65be53edcd41..95f091d732487b1d8c9b20592153a25a51dc833a
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Improved\saccuracy\sof\sfloating-point\sconversion\sconstants\sas\ssuggested\sby\n[forum:/info/598d32f6135c41c1|forum\spost\s598d32f6135c41c1].
- D 2023-06-28T11:46:28.098
 -C Simple\stest\scases\sfor\sthe\senhanced\sSUM()\sfunction.
 -D 2023-06-26T19:57:23.253
++C Enhance\sthe\sSUM()\saggregate\s(and\srelated\sAVG()\sand\sTOTAL())\sso\sthat\sthe\srunning\nsum\sis\saccurate\sto\sabout\s100\sbits.
++D 2023-06-28T12:02:48.388
  F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
  F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
  F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@@ -705,7 -705,7 +705,7 @@@ F src/trigger.c ad6ab9452715fa9a8075442
  F src/update.c 0aa36561167a7c40d01163238c297297962f31a15a8d742216b3c37cdf25f731
  F src/upsert.c 5303dc6c518fa7d4b280ec65170f465c7a70b7ac2b22491598f6d0b4875b3145
  F src/utf.c ee39565f0843775cc2c81135751ddd93eceb91a673ea2c57f61c76f288b041a0
- F src/util.c 4264102045fdb36e9af3ff361e390a5f7a76342a2bd7069e55d8ad332026d6b5
 -F src/util.c 649837c4156ac0d94a5720a08c98266c7ae5d9020c60254e15de9e68f20202de
++F src/util.c a6b41c67ff2a5379b46b77e587b2e0adb2d2ddcc5669691674ca4d28e2755ae4
  F src/vacuum.c 604fcdaebe76f3497c855afcbf91b8fa5046b32de3045bab89cc008d68e40104
  F src/vdbe.c c993304c609326cf625b4ad30cbb0e15a3f64c941cf2c9713d0c360b4abbaa98
  F src/vdbe.h 41485521f68e9437fdb7ec4a90f9d86ab294e9bb8281e33b235915e29122cfc0
@@@ -2041,8 -2041,8 +2041,9 @@@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a9
  F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
  F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
  F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
- P 9d7813ddcf67f1256e7331c5f390cb122b3f7e35cf46e0b33b610216a5396a00
- R 169687b27435f028f9845b8b7f3b29b8
 -P 439fc00fee62b4db3751860485e21a99cae4fd1f5d911b2c08651a1466245ecc
 -R 8463c5b0b92c650d275f9738ce6de95a
++P 4943e8a1819e189747eefc414d02c0485e1620deff9cf92664295b21a8a9a83c c66ef2440e4e6c7aa17b50e5a29e543713ccab69aa0a415bac29b35b6116504a
++R 51bf89677ed17bae2e4a623d6d52a0c3
++T +closed c66ef2440e4e6c7aa17b50e5a29e543713ccab69aa0a415bac29b35b6116504a
  U drh
- Z 4fc8fce670e6ce62ea8a2e6be22b995e
 -Z 784302c1094e04b5404dc9080db2bdf7
++Z 8ab32d51087d44c8fc250f900dd8d446
  # Remove this line to create a well-formed Fossil manifest.

diff --cc manifest.uuid
index d18d43c4d44942702848554c8eaf07af5ec29bb0,5f9a4ea98fe078c32e35aae52c8845c068a382e0..749907240d38d350f50932a10a6fcd609bb43f6f
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 4943e8a1819e189747eefc414d02c0485e1620deff9cf92664295b21a8a9a83c
 -c66ef2440e4e6c7aa17b50e5a29e543713ccab69aa0a415bac29b35b6116504a
++a915f15a916af698e0cef46c8b3e7ed11bda19349179d2d414073cd39c4cce24

diff --cc src/util.c
Simple merge