Refinements to pacman

[Spuds]

• consolidate browse and installed lists
• consolidate package server, upload, download, etc to single panel
• remove custom package servers
• minor refactoring + [] and hardening
• Some cleanup pkg template

[codecov[bot]]

Codecov Report

Attention: 410 lines in your changes are missing coverage. Please review.

Comparison is base (20b1f04) 32.23% compared to head (914248d) 33.07%. Report is 8 commits behind head on development.

Files	Patch %	Lines
sources/ElkArte/Packages/Packages.php	34.79%	178 Missing :warning:
sources/ElkArte/Packages/PackageServers.php	19.13%	93 Missing :warning:
sources/ElkArte/Packages/PackageActions.php	34.57%	70 Missing :warning:
sources/subs/Package.subs.php	25.00%	69 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## development #3740 +/- ## ================================================= + Coverage 32.23% 33.07% +0.84% + Complexity 16462 16456 -6 ================================================= Files 431 431 Lines 83419 83958 +539 ================================================= + Hits 26886 27767 +881 + Misses 56533 56191 -342 ```

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