Only add channel to tile request string if active

[will-moore]

Fixes #542

We previously reduced the length of query strings in ome/omero-web#201, but given images with even more channels (148 channel example in issue above), we need to reduce the length further by only including active channels.

To test, import an image (such as the sample image from issue) and check that the URLs for tiles only include active channels.

This has been imported at https://merge-ci.openmicroscopy.org/web/webclient/img_detail/1378/?dataset=871

Without this PR, the image loading fails:

The URL for loading the image tile is

https://merge-ci.openmicroscopy.org/web/webgateway/render_image/1378/0/0/?c=1|0:14221$FF0000,2|0:2251$00FF00,3|0:9582$0000FF,-4|0:990$FFE000,-5|0:1129$00E0E0,-6|0:4299$FF00E0,-7|0:465$FFCC00,-8|0:566$00FFEE,-9|0:361$FF00EE,-10|0:829$CCFF00,-11|0:9344$0CA6F2,-12|0:1058$F20C87,-13|0:16687$68F20C,-14|0:2174$0C49F2,-15|0:1193$F20C2B,-16|0:4000$0CF20C,-17|0:12174$2B0CF2,-18|0:12976$F2490C,-19|0:405$0CF268,-20|0:2836$870CF2,-21|0:1666$E6A117,-22|0:1629$17E6BC,-23|0:7562$D817E6,-24|0:2398$D8E617,-25|0:9615$17BCE6,-26|0:18084$E617A1,-27|0:4037$85E617,-28|0:2557$176AE6,-29|0:1575$E6174E,-30|0:1582$32E617,-31|0:623$2121D9,-32|0:1015$D93921,-33|0:33654$21D952,-34|0:352$6A21D9,-35|0:1003$D98321,-36|0:1395$21D99B,-37|0:3528$B421D9,-38|0:1774$D9CC21,-39|0:5628$21CCD9,-40|0:1977$D921B4,-41|0:1564$96CC29,-42|0:1393$2980CC,-43|0:8149$CC296A,-44|0:195$54CC29,-45|0:1677$293FCC,-46|0:147$CC2929,-47|0:1163$29CC3F,-48|0:2422$5429CC,-49|0:5954$CC6A29,-50|0:628$29CC80,-51|0:414$8F30BF,-52|0:3952$BFA330,-53|0:391$30BFB6,-54|0:1313$BF30B6,-55|0:2554$A3BF30,-56|0:2040$308FBF,-57|0:2117$BF307C,-58|0:1182$69BF30,-59|0:4086$3056BF,-60|0:1592$BF3043,-61|0:4038$36B336,-62|0:5303$4636B3,-63|0:1146$B35736,-64|0:3071$36B368,-65|0:8628$7836B3,-66|0:1300$B38936,-67|0:6083$36B39A,-68|0:16942$AA36B3,-69|0:431$AAB336,-70|0:1241$369AB3,-71|0:13087$A63A82,-72|0:3177$73A63A,-73|0:1794$3A65A6,-74|0:4256$A63A57,-75|0:1245$48A63A,-76|0:1234$3A3AA6,-77|2:5504$A6483A,-78|0:1393$3AA657,-79|0:1579$653AA6,-80|0:1329$A6733A,-81|0:1634$3D997A,-82|0:1334$873D99,-83|0:320$99933D,-84|0:3136$3D9399,-85|0:1581$993D87,-86|0:3494$7A993D,-87|0:1925$3D6E99,-88|0:4765$993D62,-89|0:4914$56993D,-90|0:3846$3D4999,-91|0:3916$8C3F3F,-92|0:13909$3F8C49,-93|0:1977$543F8C,-94|0:6656$8C5E3F,-95|0:4390$3F8C68,-96|0:587$733F8C,-97|0:7977$8C7D3F,-98|0:394$3F8C87,-99|0:1788$8C3F87,-100|1:14836$7D8C3F,-101|0:922$406A80,-102|0:679$804062,-103|0:5720$598040,-104|0:654$405180,-105|0:2315$804048,-106|0:10271$408040,-107|0:408$484080,-108|0:1191$805140,-109|0:2424$408059,-110|0:664$624080,-111|0:3917$73623F,-112|0:4214$3F7368,-113|0:2011$6F3F73,-114|0:4770$6F733F,-115|0:2825$3F6873,-116|0:1339$733F62,-117|0:2343$5B733F,-118|0:1857$3F5473,-119|0:3317$733F4D,-120|0:991$46733F,-121|0:5497$3D3D66,-122|0:8689$66433D,-123|0:766$3D6648,-124|0:4075$4E3D66,-125|0:860$66533D,-126|4:2213$3D6658,-127|0:8845$5E3D66,-128|0:3224$66633D,-129|0:5093$3D6366,-130|0:18167$663D5E,-131|0:4256$4F593A,-132|0:980$3A4B59,-133|0:11543$593A47,-134|0:1764$42593A,-135|0:5103$3A3E59,-136|26:4659$593A3A,-137|0:802$3A593E,-138|4:4299$423A59,-139|0:6106$59473A,-140|0:652$3A594B,-141|0:3523$45364D,-142|0:9250$4D4836,-143|0:699$364D4B,-144|0:4327$4D364B,-145|0:963$484D36,-146|0:2853$36454D,-147|0:2955$4D3642,-148|0:1640$3F4D36,-149|0:5906$363C4D,-150|0:386$4D3639,-151|0:8842$304030,-152|0:2804$323040,-153|0:1973$403430,-154|0:1806$304036,-155|0:736$383040,-156|0:2099$403A30,-157|0:4719$30403D,-158|0:15962$3F3040,-159|0:2803$3F4030,-160|0:2160$303D40,-161|0:7200$332930,-162|0:1356$2E3329,-163|0:2429$292D33,-164|0:62870$33292C,-165|0:3296$2A3329,-166|0:6599$292933,-167|0:2272$332A29,-168|0:1769$29332C,-169|0:5316$2D2933,-170|0:4833$332E29,-171|0:1407$212624,-172|0:5235$252126,-173|0:2001$262621,-174|0:2820$212626,-175|0:4457$262125,-176|0:2767$242621,-177|0:25279$212426,-178|0:2594$262123,-179|0:10737$222621,-180|0:3795$212126,-181|0:3059$1A1717,-182|0:11316$171A17,-183|0:7733$18171A,-184|0:1039$1A1817&maps=[{%22inverted%22:{%22enabled%22:false}},{%22inverted%22:{%22enabled%22:false}},{%22inverted%22:{%22enabled%22:false}},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{},{}]&m=g&p=normal&q=0.9

And the response is:

Request Line is too large (4111 > 4094)

[will-moore]

Temporarily excluding to check that images with many channels fail to render on merge-ci...

EDIT: PR was excluded (see above)...

[pwalczysko]

checked on merge-ci, lgtm, thank you