Replacing existing browser tree node png icons with the svg icons. Made

it compatible with the pgAdmin 4 color combination.

TODO::
Icons for the following nodes are in PNG format.
- Domain Constraint (Only the invalid icon)
- pgAgent Job Steps
- Green Plum database server
- Server (Only server.png, which is used in the create/edit dialog)

web/pgadmin/browser/server_groups/servers/databases/static/img/coll-database.svg

@@ -0,0 +1 @@
+<svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16"><defs><style>.cls-1{fill:#def4fd;}.cls-2{fill:#2980b9;}</style></defs><title>coll-database</title><path class="cls-1" d="M10.82,4.5A.87.87,0,0,0,11,4c0-1.1-2.46-2-5.5-2S0,2.9,0,4a.87.87,0,0,0,.18.5A.87.87,0,0,0,0,5a.87.87,0,0,0,.18.5.78.78,0,0,0,0,1,.78.78,0,0,0,0,1,.78.78,0,0,0,0,1,.78.78,0,0,0,0,1A.87.87,0,0,0,0,10c0,1.1,2.46,2,5.5,2s5.5-.9,5.5-2a.87.87,0,0,0-.18-.5.78.78,0,0,0,0-1,.78.78,0,0,0,0-1,.78.78,0,0,0,0-1,.78.78,0,0,0,0-1A.87.87,0,0,0,11,5,.87.87,0,0,0,10.82,4.5Z"/><ellipse class="cls-2" cx="5.5" cy="4" rx="5.5" ry="2"/><path class="cls-2" d="M5.5,11C2.94,11,.79,10.36.18,9.5A.87.87,0,0,0,0,10c0,1.1,2.46,2,5.5,2s5.5-.9,5.5-2a.87.87,0,0,0-.18-.5C10.21,10.36,8.06,11,5.5,11Z"/><path class="cls-2" d="M5.5,8C2.94,8,.79,7.36.18,6.5A.87.87,0,0,0,0,7C0,8.1,2.46,9,5.5,9S11,8.1,11,7a.87.87,0,0,0-.18-.5C10.21,7.36,8.06,8,5.5,8Z"/></svg>

web/pgadmin/browser/server_groups/servers/databases/static/img/database.svg

@@ -0,0 +1 @@
+<svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16"><defs><style>.cls-1{fill:#def4fd;}.cls-2{fill:#2980b9;}</style></defs><title>database</title><path class="cls-1" d="M10.82,4.5A.87.87,0,0,0,11,4c0-1.1-2.46-2-5.5-2S0,2.9,0,4a.87.87,0,0,0,.18.5.78.78,0,0,0,0,1,.78.78,0,0,0,0,1,.78.78,0,0,0,0,1,.78.78,0,0,0,0,1,.78.78,0,0,0,0,1A.87.87,0,0,0,0,10c0,1.1,2.46,2,5.5,2s5.5-.9,5.5-2a.87.87,0,0,0-.18-.5.78.78,0,0,0,0-1,.78.78,0,0,0,0-1,.78.78,0,0,0,0-1,.78.78,0,0,0,0-1A.78.78,0,0,0,10.82,4.5Z"/><ellipse class="cls-2" cx="5.5" cy="4" rx="5.5" ry="2"/><path class="cls-2" d="M5.5,11C2.94,11,.79,10.36.18,9.5A.87.87,0,0,0,0,10c0,1.1,2.46,2,5.5,2s5.5-.9,5.5-2a.87.87,0,0,0-.18-.5C10.21,10.36,8.06,11,5.5,11Z"/></svg>

web/pgadmin/browser/server_groups/servers/databases/static/img/databasebad.svg

@@ -0,0 +1 @@
+<svg id="Layer_1" data-name="Layer 1" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16"><defs><style>.cls-1{fill:#f2f2f2;}.cls-2{fill:#717f8e;}.cls-3{fill:none;stroke:#d0021b;stroke-linecap:round;stroke-linejoin:round;stroke-width:1.5px;}</style></defs><title>databasebad</title><path class="cls-1" d="M11.82,5.5A.87.87,0,0,0,12,5c0-1.1-2.46-2-5.5-2S1,3.9,1,5a.87.87,0,0,0,.18.5.78.78,0,0,0,0,1,.78.78,0,0,0,0,1,.78.78,0,0,0,0,1,.78.78,0,0,0,0,1,.78.78,0,0,0,0,1A.87.87,0,0,0,1,11c0,1.1,2.46,2,5.5,2s5.5-.9,5.5-2a.87.87,0,0,0-.18-.5.78.78,0,0,0,0-1,.78.78,0,0,0,0-1,.78.78,0,0,0,0-1,.78.78,0,0,0,0-1,.78.78,0,0,0,0-1Z"/><ellipse class="cls-2" cx="6.5" cy="5" rx="5.5" ry="2"/><path class="cls-2" d="M6.5,12c-2.56,0-4.71-.64-5.32-1.5A.87.87,0,0,0,1,11c0,1.1,2.46,2,5.5,2s5.5-.9,5.5-2a.87.87,0,0,0-.18-.5C11.21,11.36,9.06,12,6.5,12Z"/><line class="cls-3" x1="12.5" y1="2.5" x2="9.5" y2="5.5"/><line class="cls-3" x1="12.5" y1="5.5" x2="9.5" y2="2.5"/></svg>